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 Posted - 08/18/2005 : 04:33:25
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PT J
AU Ciurchea, D
TI Structure and superconducting properties of (Bi,Pb): 2223 superconductor with 3D excess conductivity
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB The full pattern decomposition method by Le Bail was applied to a single phase orthorhombic (Bi,Pb):2223 superconductor with an accentuated three dimensional excess conductivity The space group Pmam, with the lattice parameters a = 5.2598, b = 5.5381, c = 37.174 Angstrom was found. The Fourier maps derived show that delocalization of the Sr atoms induces terracing of the Cu/Ca/Cu superconducting stacking of 0.3 Angstrom, close to the c-axis coherence length, yielding the three dimensional character of the conduction evidenced by the resistivity measurements.
C1 Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
RP Ciurchea, D, Univ Babes Bolyai, Fac Phys, 1 Kogalniceanu, R-3400 Cluj Napoca, Romania.
CR 1997, INORGANIC CRYSTAL ST
1998, PDF FILES SETS 1 46
1999, CRYSTALLOGRAPHICA SE
AMOROS P, 1988, EUR J SOL STATE INOR, V25, P599
ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
CIURCHEA D, 1996, SUPERCOND SCI TECH, V9, P88
CIURCHEA D, 2001, INT J MOD PHYS B, V15, P157
CIURCHEA D, 2002, INT J MOD PHYS B, V16, P583
FISHER DS, 1995, PHYS REV B, V51, P6411
HALIASTOU M, 1997, SUPERCOND SCI TECH, V10, P712
HATANO T, 1994, J APPL PHYS, V75, P2141
HATANO T, 1996, BISMUTH BASED HIGH T, P545
HUNTER BA, 1997, RIETICA VERSION 1 67
LAUGIER J, 2000, ECOLE NATL SUPERIEUR
LEBAIL A, 1988, MAT RES B, V23, P447
MAJEWSKI PJ, 1996, BISMUTH BASED HIGH T, P129
POP AV, 2000, INT J MOD PHYS B, V14, P1567
POP AV, 2000, PHYSICA B 1, V284, P1101
PRINCE E, 1993, RIETVELD METHOD
SCHNEIDER T, 1988, Z PHYS B, V73, P5
SHI DL, 1989, PHYS REV B, V39, P9091
TAKAYANAGI T, 2002, J PHYS-CONDENS MAT, V14, P1361
WONGNG W, 1999, J RES NATL INST STAN, V104, P277
TC 0
PD JUN 20
PY 2003
VL 17
IS 15
BP 2851
EP 2861
UT ISI:000184510300005
ER
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PT J
AU Tarsiche, I
Ciurchea, D
TI Determination of diffusion parameters of CO2 through microporous PTFE using a potentiometric method
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB Dk values at the diffusion of CO2 through microporous PTFE of 1 to 7 x 10(-7) cm(2) s(-1) in the concentration range from 4 x 10(-4) to 0.22 g/l CO2 are determined using a simple, fast and reliable potentiometric method. The method is based on the least-squares fitting of the potential versus time response of a self made CO2 sensitive Severinghaus type sensor with PTFE as a gas-permeable membrane. The obtained results are in good agreement with other reported literature data, both experimental or calculated ones using molecular dynamics simulations. The proposed technique is very sensitive especially at low concentrations of gas and may be used for the study of other polymeric membranes too.
C1 Univ Babes Bolyai, Inst Chem Raluca Ripan, R-3400 Cluj Napoca, Romania.
Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
RP Tarsiche, I, Univ Babes Bolyai, Inst Chem Raluca Ripan, 30 Fantanele, R-3400 Cluj Napoca, Romania.
CR BAILEY PL, 1975, ANALYST, V100, P145
BARRE RM, 1951, DIFFUSION SOLIDS
BUFFLE J, 1981, ELECTROANAL CHEM, V129, P67
CIURCHEA D, 2001, RESURSE PROGRAME STI
CRANK J, 1968, DIFFUSION POLYM
FAULON JL, 1997, SC97 HIGH PERFORMANC
FRIED JR, 2000, COMPUT THEOR POLYM S, V10, P447
JENSEN MA, 1972, ANAL CHEM, V51, P55
LIU X, 2001, CHEM MATER, V13, P3449
ROSS JW, 1973, J PURE APPL CHEM, V36, P437
TARSICHE I, 1997, MEAS SCI TECHNOL, V8, P1367
TARSICHE I, 1999, LAB ROBOTICS AUTOMAT, V11, P224
TARSICHE I, 2001, SENSOR ACTUAT B-CHEM, V72, P94
TC 0
PD SEP 10
PY 2002
VL 16
IS 23
BP 3473
EP 3480
UT ISI:000178300300008
ER
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PT J
AU Ciurchea, D
TI Structural aspects of the false 2212 in a (Bi,Pb): 2223 superconductor
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB The full pattern decomposition method by Le Bail was applied to the X-ray diffraction pattern of a (Bi1.8Pb0.46)Sr1.88Ca2.06(Cu0.97Fe0.01Ca0.02)(3)O-y superconductor presenting the same characteristics as the false 2212 reported by Masqood et al. (ICDD file 42-514). By using the Cmmm space group, AB(5) coordination in the BiO planes was evidenced, yielding an explanation for the apparent cell colapse. Orthorombic-pseudohexagonal settings for the a and b lattice constants may be derived from the group-supergroup relationships, i.e. instead of a approximate to b approximate to 5.38 Angstrom = 3.8 x root2 Angstrom one may take a = 2 x 3.8 Angstrom and b = 3.8 x root3/2 Angstrom. Indexing with these values avoids the assumption for the strange (00 (11) under bar) peak, and yields the refined values of a = 7.664 Angstrom, b = 3.356 Angstrom and c = 16.172 Angstrom, space group Pmmm.
C1 Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
RP Ciurchea, D, Univ Babes Bolyai, Fac Phys, 1 Kogalniceanu, R-3400 Cluj Napoca, Romania.
CR 1999, CRYSTALLOGRAPHICA SE
*INT CTR DIFFR DAT, 42514 ICDD
AMOROS P, 1988, EUR J SOL STATE INOR, V25, P599
CIURCHEA D, 1996, SUPERCOND SCI TECH, V9, P88
HAHN T, 1983, INT TABLES XRAY CRYS, A
HATANO T, 1996, BISMUTH BASED HIGH T, P545
HENN R, 1994, PHYSICA C, V221, P405
HUNTER BA, 2000, RIETICA 167
KRAUS W, 1999, POWDER CELL WINDOWS
LAUGIER J, 2000, CELREF 2
LEBAIL A, 1988, MAT RES B, V23, P447
MAJEWSKI PJ, 1996, BISMUTH BASED HIGH T, P129
MARECHAL C, 1998, PHYSICA C, V294, P23
MASQOOD A, 1990, MAT RES B, V25, P779
NOVOMLINSKY LA, 1994, MATER SCI FORUM, V166, P783
OHKUBO M, 1995, APPL PHYS LETT, V67, P2403
WONGNG W, 1999, J RES NATL INST STAN, V104, P277
YANG JL, 1990, MOD PHYS LETT B, V4, P791
ZHU X, 1989, MOD PHYS LETT B, V3, P707
TC 1
PD FEB 10
PY 2002
VL 16
IS 4
BP 583
EP 592
UT ISI:000174474900004
ER
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PT J
AU Ciurchea, D
TI Structure and superconducting characteristics of a defective (Bi1.6Pb0.4)(Sr1.8Ba0.2)(Ca1.96Lu0.04)Cu3Oy superconductor
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB Full pattern decomposition was applied to the X-ray diffraction patteren of a single phase orthorhombic (Bi1.6Pb0.4) (Sr1.8Ba0.2) (Ca1.96Lu0.04)Cu3Oy superconductor. Delocalization of the Sr atoms induces terracing of the Cu/Ca/Cu superconducting stacking up to 0.6 Angstrom, in the range of the c-axis coherence length. This yields a three dimensional character of the conduction evidenced in the resistivity measurements also. The effect is direct consequence of the loss of symmetry implied by the orthorhombic structure.
C1 Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
RP Ciurchea, D, Univ Babes Bolyai, Fac Phys, Kogalniceanu 1, R-3400 Cluj Napoca, Romania.
CR 1999, OXFORD CRYOSYTEMS
*FACH, 1997, IN CRYST STRUCT DAT
*INT CTR DIFFR DAT, 1998, PDF FIL SETS 1 46
AMOROS P, 1988, EUR J SOL STATE INOR, V25, P599
ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
CIURCHEA D, 1996, SUPERCOND SCI TECH, V9, P88
CIURCHEA D, 1998, GEN SCI M SOC BELG P, V32
FISHER DS, 1995, PHYS REV B, V51, P6411
HALIASTOU M, 1997, SUPERCOND SCI TECH, V10, P712
HATANO T, 1994, J APPL PHYS, V75, P2141
HATANO T, 1996, BISMUTH BASED HIGH T, P545
HUNTER BA, 2000, ANSTO
LAUGIER J, 2000, ECOLE NATL SUPERIEUR
LEBAIL A, 1988, MAT RES B, V23, P447
PRINCE E, 1993, RIETVELD METHOD
SCHNEIDER T, 1988, Z PHYS B, V73, P5
SHI DL, 1989, PHYS REV B, V39, P9091
TC 1
PD JAN 20
PY 2001
VL 15
IS 2
BP 157
EP 165
UT ISI:000167448600005
ER
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PT J
AU Tarsiche, I
Ciurchea, D
TI Permeability of PTFE studied with a potentiometric SO2-sensitive sensor
SO SENSORS AND ACTUATORS B-CHEMICAL
AB Permeability of PTEE to SO2 is studied by the least-squares fitting of the dynamic response of a potentiometric sensor with PTFE as gas-permeable membrane.
The proposed method establishes D x k product values for the diffusion of SO2 through PTFE that may be compared with the reported D x k product value at the diffusion through dimethylsilocone rubber. It also evidences morphology differences between the considered PTFE samples, especially in the low concentration range that yield to the very long recovery time of the sensor, i.e. the variation of the superficial tension in the triphasic SO2/PTFE/internal electrolyte system.
The method is accessible and may be used for the study of the permeability of other polymeric membranes or triphasic systems. (C) 2001 Elsevier Science B.V. All rights reserved.
C1 Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
Inst Chem Raluca Ripan, Cluj Napoca 3400, Romania.
RP Ciurchea, D, Univ Babes Bolyai, Fac Phys, 1 M Kogalniceanu Str, R-3400 Cluj Napoca, Romania.
CR CIURCHEA D, 1997, METODE SI PROGRAMME, P146
DAVIDSON JSD, 1980, CAN J PHYSL PHARM, V58, P550
IVANOV IB, 1978, J COLLOID INTERF SCI, V63, P166
MANCA D, 1989, INT J ENVIRON AN CH, V36, P55
PARKER D, 1978, MED BIOL ENG COMPUT, V16, P599
ROSS JW, 1973, PURE APPL CHEM, V36, P473
SCHULZE HJ, 1981, PHYSIKALISH CHEM ELE, P78
STEKENMESSER H, 1977, FREIBERGER FORSCH A, V568, P61
TARSICHE I, 1997, MEAS SCI TECHNOL, V8, P1367
TARSICHE I, 1999, LAB ROBOTICS AUTOMAT, V11, P224
TC 1
PD JAN 5
PY 2001
VL 72
IS 1
BP 94
EP 98
UT ISI:000166340600014
ER
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PT J
AU Pop, AV
Deac, IG
Ilonca, G
Ciurchea, D
Pop, V
TI Effects of Y, Er and Lu substitution upon superconductivity in (Bi,Pb): 2223 system
SO PHYSICA B-CONDENSED MATTER
AB The effect of partial substitution of Ca by x = 0.02Y, 0.02Er and 0.02Ln in the (Bi,Pb):2223 superconductor was investigated by resistivity and AC susceptibility measurements. The rate of depression for T-c in x = 0.02 samples is found to be almost the same for all substituents. Residual resistivity varies according to the type of substituting ions. The linear dependence of intergranular temperature T-p as a function of AC field amplitude agrees with Muller critical state model. (C) 2000 Elsevier Science B.V. All rights reserved.
C1 Univ Babes Bolyai, Fac Phys, Cluj Napoca 3400, Romania.
RP Pop, AV, Univ Babes Bolyai, Fac Phys, Str M Kogalniceanu 1, Cluj Napoca 3400, Romania.
CR GAO Y, 1992, PHYS REV B, V45, P7436
MULLER KH, 1989, PHYSICA C, V159, P717
POP AV, 1996, J ALLOY COMPD, V241, P116
SUMANA PP, 1994, PHYS REV B, V50, P6929
TC 4
PD JUL
PY 2000
VL 284
PN Part 1
BP 1101
EP 1102
UT ISI:000087311700549
ER
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PT J
AU Tarsiche, I
Ciurchea, D
Reghini, D
TI Enzimatic sensor for urea
SO REVISTA DE CHIMIE
AB The paper deals with an enzyme sensor for urea based on a selfmade potentiometric NH3-sensitive sensor with teflon as gas permeable membrane. The optimum electrodic function conditions were established. The functional characteristics of the enzyme sensor are also presented.
C1 Inst Chim Raluca Ripan, Cluj Napoca, Romania.
Univ Bebes Bolyai, Fac Fiz, Cluj Napoca, Romania.
RP Tarsiche, I, Inst Chim Raluca Ripan, Cluj Napoca, Romania.
CR CIURCHEA D, 1997, METODE PROGRAME PENT
GUILBAULT GG, 1974, ANAL CHIM ACTA, V73, P355
GUILBAULT GG, 1975, ANAL CHIM ACTA, V76, P237
JOHANSSON G, 1976, ANAL CHIM ACTA, V84, P23
LITEANU C, 1979, TEORIA METODOLOGIA S
MASCINI M, 1977, ANAL CHEM, V49, P795
PAPASTATHOPOULO.DS, 1975, ANAL CHIM ACTA, V79, P17
PUI PG, 1978, ANAL CHEM, V2, P330
WATSON B, 1977, ANAL LETT, V9, P713
TC 0
PD DEC
PY 1999
VL 50
IS 12
BP 847
EP 851
UT ISI:000086319100003
ER
--------------------------------------------------------------------------------
PT J
AU Tarsiche, I
Ciurchea, D
Madau, P
Olenic, L
TI On-line analysis of NH3, CO2, and SO2 diffusion through microporous teflon
SO LABORATORY ROBOTICS AND AUTOMATION
AB Dynamic responses of self-made potentiometric NH3, CO2, and SO2 sensitive gas sensors are followed in the 10(-5)-5 x 10(-3)M concentration range. By least squares fitting of potential versus time curves, Dk product values at the diffusion of NH3, CO2, and SO2 through microporous Teflon are calculated. The obtained results are fairly reflected by the behavior of the sensor. Measurements of potential versus time in mixed solutions of CO2 and SO2 with the CO2 sensitive sensor indicate the presence of the interferent. (C) 1999 John Wiley & Sons, Inc.
C1 Univ Babes Bolyai, Fac Phys, Cluj Napoca 3400, Romania.
Inst Chem Raluca Ripan, Cluj Napoca 3400, Romania.
Free Univ Brussels, Serv Chim Ind & Analyt, B-1050 Brussels, Belgium.
RP Ciurchea, D, Univ Babes Bolyai, Fac Phys, Kogalniceanu Str 1, Cluj Napoca 3400, Romania.
CR ATTILI AF, 1975, BIOCHEM MED, V14, P109
BUFFLE J, 1981, J ELECTROANAL CHEM, V129, P67
CIURCHEA D, 1997, BALKAN PHYS LETT S, V5, P1829
CIURCHEA D, 1997, METODE SI PROGRAMME, P146
LEBUY A, 1982, BIOTECHNOL LETT, V4, P303
MANCA D, 1989, INT J ENVIRON AN CH, V36, P55
PARK NJ, 1973, J CLIN PATHOL, V26, P802
ROSS JW, 1975, ANAL CHEM, V36, P473
SOUREK R, 1983, CHEM PRUN, V33, P297
TARSICHE I, 1997, MEAS SCI TECHNOL, V8, P1367
TC 3
PY 1999
VL 11
IS 4
BP 224
EP 228
UT ISI:000081987700007
ER
--------------------------------------------------------------------------------
PT J
AU De Boeck, C
Ciurchea, D
Duvigneaud, PH
TI Iron doping effect on composition and microstructure of Bi2.05Sr1.9Ca1.05 (Cu1-xFex)(2)O8+delta(0 <= x <= 0.15) superconductors
SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
AB Samples with Bi2.05Sr1.9Ca1.05(Cu1-xFex)(2)O8+delta (0 less than or equal to x less than or equal to 0.15) compositions were synthesized by a liquid-mix process able to give single phase compounds. The superconducting phase was carefully investigated by SEM and EDX. Substitution of x Fe atoms in the Bi2Sr2CaCu2O8+delta grains corresponds to the removal of 1.7x Cu atoms and to the addition of 0.75x Bi atoms whereas the sum Sr + Ca remains quite constant. In a first step, this evolution may be explained by the following basic model. Fe2O3-->2Fe(cu)(.) + V-cu" + 3 CuO which assumes the creation of vacancies in the copper sites of the Bi2Sr2CaCu2O8+delta lattice. However, the apparent increase of Bi content suggests the formation of microdomains of Bi2Sr2CuO6 phase intergrown in the Bi2.05Sr1.9Ca1.05(Cu1-xFex)(2)O8+delta grains, as inferred from X-ray diffraction and SEM which reveals the concomitant (SrCa)(14)Cu24O41 secondary phase. The EDX results are more consistent with a Bi2Sr2CuO6-Bi2Sr2CaCu2O8+delta intergrowth model in which Fe is accommodated in the Bi2Sr2CuO6 microdomains than with the model of substitution in a Bi2Sr2CaCu2O8+delta single phase. (C) 1999 Elsevier Science Limited All rights reserved.
C1 Free Univ Brussels, Lab Chim Ind & Analyt, B-1050 Brussels, Belgium.
RP Duvigneaud, PH, Free Univ Brussels, Lab Chim Ind & Analyt, CP165,50 Ave FD Roosevelt, B-1050 Brussels, Belgium.
CR BHARGAVA SC, 1993, J PHYS-CONDENS MAT, V5, P4541
BOEKHOLT M, 1992, PHYSICA C, V198, P33
BREMERT O, 1989, J APPL PHYS, V65, P1018
DEBOECK C, 1993, P 3 JOURN ET CAEN
DEBOECK C, 1994, PHYSICA C 1, V235, P329
DEBOECK C, 1994, PHYSICA C, V235, P317
DEBOECK C, 1997, THESIS U LIBRE BRUXE
DIKO P, 1993, J AM CERAM SOC, V76, P2859
DUVIGNEAUD PH, 1998, SUPERCOND SCI TECH, V11, P116
GU GD, 1994, INT CERAM MONOGR, V1, P1210
HOLESINGER TG, 1992, PHYSICA C, V202, P109
HORIUCHI S, 1996, BISMUTH BASED HIGH T, P7
LEPAGE Y, 1989, PHYS REV B, V40, P6810
MAEDA A, 1990, PHYS REV B, V41, P4112
MAJEWSKI PJ, 1996, BISMUTH BASED HIGH T, P129
MEHBOD M, 1988, PHYS REV B B, V38, P11813
MEHBOD M, 1990, J LESS-COMMON MET, V164, P536
MEHBOD M, 1990, PHYSICA C, V168, P265
MULLER R, 1992, PHYSICA C, V203, P299
RAO KVR, 1992, PHYSICA C, V192, P419
TANG H, 1990, J APPL PHYS, V67, P4512
VOMHEDT B, 1994, PHYS REV B, V49, P9898
YANAGISAWA K, 1993, PHYSICA C, V208, P51
TC 1
PY 1999
VL 19
IS 6-7
BP 1537
EP 1541
UT ISI:000080025200183
ER
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PT J
AU Pop, AV
Deltour, R
Harabor, A
Ciurchea, D
Ilonca, G
TI Ac susceptibility study of the inter- and intragranular properties in (Bi,Pb): 2223 superconductor
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB The temperature and amplitude of AC field dependencies of both inter- and intragranular T-p and T-g temperatures of the imaginary peaks of chi " has been studied for a sintered single phase (Bi,Pb):2223 superconductor. The AC field dependencies for T-p and T-g and the relation between inter-and intragrain force densities were discussed by using Muller critical-state model. From the chi "(T) curve, the values of intergrain magnetic critical current density J(cJ) was obtained via the application of Bean's critical state model. J(cJ)(T) dependence near T-c agree with the assumption of SNS intergrain junctions.
C1 Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
Free Univ Brussels, B-1050 Brussels, Belgium.
Univ Craiova, Fac Sci, Craiova 1100, Romania.
RP Pop, AV, Univ Babes Bolyai, Fac Phys, R-3400 Cluj Napoca, Romania.
CR AMBEGAOKAR V, 1969, PHYS REV LETT, V22, P1364
ANDERSON PW, 1962, PHYS REV LETT, V9, P309
ANGUREL LA, 1994, PHYSICA C, V230, P361
BALADINI A, 1996, PHYSICA C, V262, P68
BEAN CP, 1964, REV MOD PHYS, V36, P31
CHEN DX, 1989, CRYOGENICS, V29, P800
CLEM JR, 1988, PHYSICA C, V153, P50
CLEM JR, 1988, PHYSICA C, V153, P9848
DEGENNES PG, 1966, SUPERCONDUCTIVITY ME
GONZALEZ JL, 1995, PHYSICA C, V255, P76
GROSS R, 1990, PHYS REV LETT, V64, P228
HENSEL B, 1993, PHYSICA C, V205, P329
HIKATA T, 1990, CRYOGENICS, V30, P924
KIM YB, 1963, PHYS REV, V129, P528
MULLER KH, 1989, PHYSICA C, V158, P69
MULLER KH, 1989, PHYSICA C, V159, P717
PETERSON RL, 1988, PHYS REV B, V37, P9848
POP AV, 1996, J ALLOY COMPD, V241, P116
POP AV, 1996, MOD PHYS LETT B, V10, P1453
YAMAMOTO K, 1993, PHYS REV B, V47, P915
TC 13
PD NOV 20
PY 1997
VL 11
IS 29
BP 3461
EP 3467
UT ISI:000071261300006
ER
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PT J
AU Pop, AV
Deltour, R
Harabor, A
Ciurchea, D
Ilonca, G
Pop, V
Todica, M
TI Effect of Fe substitution for Cu in the mixed state of (Bi,Pb):2223 superconductor
SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY
AB The effect of the partial substitution of x = 0.02 Fe for Cu in the stabilized (Bi, Pb):2223 phase has been investigated by magnetoresistivity measurements up to 0.7 T. The intra-and intergranular transitions as a function of magnetic field were analysed using d(rho)/dT versus 7 curves.
The Arrhenius plots are represented by a family of straight lines. The activation energy is proportional to (1 - T/T-c) In B. The main dissipation process is related to the vortex cutting mechanism.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
UNIV CRAIOVA,FAC SCI SOLID STATE PHYS,CRAIOVA 1100,ROMANIA.
TECH UNIV,DEPT PHYS,CLUJ NAPOCA 3400,ROMANIA.
RP Pop, AV, UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR FUCHS G, 1995, PHYSICA C, V247, P340
GONZALEZ JL, 1995, PHYSICA C, V255, P76
HENSEL B, 1993, PHYSICA C, V205, P329
HU QY, 1995, PHYSICA C, V250, P7
KES PH, 1989, SUPERCOND SCI TECH, V1, P242
KODOWAKI K, 1994, SUPERCOND SCI TECH, V7, P519
LI Y, 1994, PHYSICA C 2, V235, P1247
MULLER KH, 1994, PHYS REV B, V50, P10218
NELSON DR, 1989, PHYS REV B, V39, P9158
NKUM RK, 1995, SUPERCOND SCI TECH, V8, P822
NOETZEL R, 1996, PHYSICA C, V260, P290
OBUKHOV SP, 1990, PHYS REV LETT, V65, P1279
PALSTRA TTM, 1988, PHYS REV LETT, V61, P1662
PALSTRA TTM, 1990, PHYS REV B, V41, P6621
POP AV, 1996, J ALLOY COMPD, V241, P116
POP AV, 1996, MOD PHYS LETT B, V10, P1453
QIU XG, 1993, PHYS REV B, V47, P14519
QIU XG, 1995, PHYS REV B, V52, P559
RAVI S, 1994, PHYS REV B, V49, P13082
TINKHAM M, 1988, PHYS REV LETT, V61, P658
TITTONEN I, 1990, PHYS REV B, V42, P4212
VONHEDT B, 1994, PHYS REV B, V49, P9898
WAGNER P, 1995, PHYS REV B, V51, P1206
TC 10
PD NOV
PY 1997
VL 10
IS 11
BP 843
EP 846
UT ISI:A1997YG60000009
ER
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PT J
AU Tarsiche, I
Hopirtean, E
Ciurchea, D
TI Least-squares analysis of ammonia diffusion through PTFE membranes
SO MEASUREMENT SCIENCE & TECHNOLOGY
AB The dynamic response of a potentiometric ammonia sensitive sensor is analysed by least squares fitting of potential versus time curves by using the model described by Ross at al. The parameters found yield the values of the product Dk reliably and reproduce the response and recovery time characteristics of the sensor when the type of gas-permeable membrane is changed.
C1 UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
RP Tarsiche, I, INST CHEM RALUCA RIPAN,CLUJ NAPOCA 3400,ROMANIA.
CR BAILEY PL, 1975, ANALYST, V100, P145
BARRER RM, 1951, DIFFUSION SOLIDS
CIURCHEA D, 1995, PRELUCRAREA DATELOR
HATO M, 1983, ANAL CHIM ACTA, V149, P193
JENSEN MA, 1979, ANAL CHEM, V51, P1972
PASTERNAK RA, 1970, MACROMOLECULES, V3, P366
POKLUDOVA E, 1973, KOZARSTOI, V23, P1770
ROSS JW, 1973, J PURE APPL CHEM, V36, P437
TC 5
PD NOV
PY 1997
VL 8
IS 11
BP 1367
EP 1371
UT ISI:A1997YE88300026
ER
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PT J
AU Pop, AV
Ciurchea, D
Ilonca, G
Harabor, A
Deltour, R
TI Superconducting properties in bulk (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca2Cu3Oy system
SO PHYSICA C
AB U(H,T) dependenceies for activation energies obtained from Arrhenius plots were well explained by vortex cutting mechanism in an entangled vortex phase. J(cJ)(T) dependenceies near T-c from chi ''(T) agree with TAPS in the case of SNS-Josephson junctions.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
RP Pop, AV, UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR OBUKHOV SP, 1990, PHYS REV LETT, V65, P1279
WAGNER P, 1995, PHYS REV B, V51, P1206
TC 3
PD AUG
PY 1997
VL 282
PN Part 4
BP 2365
EP 2366
UT ISI:A1997YA41700212
ER
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PT J
AU Ilonca, G
Pop, AV
Ciurchea, D
Corega, C
Ilonca, M
Deltour, R
TI Transport phenomena in (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca-2(Cu1-xFex)(3)O-y thin films
SO PHYSICA C
AB Measurements of resistivity, Nernst, Seebeck and Hall effects in the mixed state and in the fluctuation regime above Tco of Bi 2223 doped with Fe (0 less than or equal to x less than or equal to 0.05) epitaxial thin films for magnetic fields between 0 and 5 T and temperature range 4- 150 K are reported. The critical field slope dBc(2)/dT, xi ab and lambda ab dependence of iron content was obtained. The universal power law rho(xy) = a(-1)rho(XX)(beta) was valide at low temperature. The experimental data are in agreement with the predication of time-dependent Ginzburg-Landau theory.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
RP Ilonca, G, UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR CALZONA V, 1995, PHYSICA C, V246, P169
HUEBENER RP, 1990, PHYS REV B, V42, P4831
HUEBENER RP, 1990, PHYSICA C, V168, P605
ILONCA G, 1996, CZECH J PHYS S2, V46, P1181
RI HC, 1993, PHYS REV B, V47, P12312
VINOKUR VM, 1993, PHYS REV LETT, V71, P1242
TC 5
PD AUG
PY 1997
VL 282
PN Part 3
BP 1257
EP 1258
UT ISI:A1997XZ90600068
ER
--------------------------------------------------------------------------------
PT J
AU Pop, AV
Deltour, R
Ciurchea, D
Harabor, A
Ilonca, G
Coldea, S
TI Activation energies in the vortex liquid state of bulk (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca2Cu3Oy superconductor
SO MODERN PHYSICS LETTERS B
AB Magnetoresistivity measurements as a function of temperature, rho(B, T) in applied magnetic field B up to 0.7 T have been carried out on a sample of the 110 K phase of the (Bi, Pb)-(Sr, Ba)-Ca-Cu-O system. The d rho/dT versus T curves in an applied magnetic field reveal the intra- and intergranular transitions. The behavior of these transitions as function of the magnetic field is presented. Thermally activated flux motion has been studied. The activation energy is proportional to (1 - T/T-c) In B, and suggests a 2D-state in which the dissipation is dominated by the cutting mechanism in an entangled flux liquid.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
UNIV CRAIOVA,FAC SCI,CRAIOVA 1100,ROMANIA.
RP Pop, AV, UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR AMBEGAOKAR V, 1969, PHYS REV LETT, V22, P1364
ANDERSON PW, 1964, REV MOD PHYS, V36, P39
BRUNNER O, 1991, PHYS REV LETT, V67, P1354
CIURCHEA D, 1996, SUPERCOND SCI TECH, V9, P88
FEIGELMAN MV, 1990, PHYSICA C, V167, P177
FUCHS G, 1995, PHYSICA C, V247, P340
GONZALEZ JL, 1995, PHYSICA C, V255, P76
GROSS R, 1990, PHYS REV LETT, V64, P228
HENSEL B, 1993, PHYSICA C, V205, P329
ICHIKAWA F, 1996, PHYSICA C, V264, P275
JENSEN HJ, 1992, EUROPHYS LETT, V20, P463
KODOWAKI K, 1994, SUPERCOND SCI TECH, V7, P519
MULLER KH, 1994, PHYS REV B, V50, P10218
NKUM RK, 1995, SUPERCOND SCI TECH, V8, P822
NOETZEL R, 1996, PHYSICA C, V260, P290
OBUKHOV SP, 1990, PHYS REV LETT, V65, P1279
PALSTRA TTM, 1990, PHYS REV B, V41, P6621
POP AV, 1996, INT J MOD PHYS B, V10, P967
QIU XG, 1993, PHYS REV B, V47, P14519
QIU XG, 1995, PHYS REV B, V52, P559
RAVI S, 1994, PHYS REV B, V49, P13082
SATO K, 1990, APPL PHYS LETT, V57, P1928
SVOBODA P, 1990, PHYSICA C, V167, P188
TINKHAM M, 1989, SOLID STATE PHYS, V42, P91
VINOKUR VM, 1990, PHYSICA C, V168, P29
VINOKUR VM, 1991, PHYS REV LETT, V67, P915
WAGNER P, 1994, PHYS REV B, V49, P13184
WAGNER P, 1995, PHYS REV B, V51, P1206
WHITE WR, 1993, PHYS REV LETT, V70, P670
YE M, 1996, PHYSICA C, V258, P95
TC 2
PD DEC 20
PY 1996
VL 10
IS 29
BP 1453
EP 1460
UT ISI:A1996WG63100004
ER
--------------------------------------------------------------------------------
PT J
AU Harabor, A
Pop, AV
Deltour, R
Schroeder, J
Ciurchea, D
Ilonca, G
TI Intergranular critical currents and excess conductivity in the Fe-substituted Bi-2223 high Tc superconductor
SO JOURNAL OF LOW TEMPERATURE PHYSICS
AB In this paper we present the effect of iron substitution in the (Bi1.6Pb0.4)(Sr(1.88)Bu(0.2))Ca-2(Cu1-xFex)(3.1) O-y system. From the resistivity and AC susceptibility data we observed that a monotonic decrease of T-c occurs with increasing Fe concentration. A strong reduction of J(c) (calculated from AC susceptibility data performed at low magnetic fields in the range 0.4A/m-800A/m) is observed in the doped samples. The crossover temperature from the Anderson-Kin thermally activated flux creep to the thermally activated phase slippage behaviour is depending on the doping concentration. The excess conductivity and 2D-3D crossover is well described by considering Delta sigma/sigma(0) as a product of a Gaussian centered at T-c with a Student distribution centered at 2T(c). The alteration of 2D dimensionality above T-c by doping results in the decrease of the number of freedom degrees of the Student distribution.
C1 UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
RP Harabor, A, FREE UNIV BRUSSELS,CAMPUS PLAINE,CP 233,B-1050 BRUSSELS,BELGIUM.
CR AMBEGAOKAR V, 1969, PHYS REV LETT, V22, P1364
ANDERSON PW, 1964, REV MOD PHYS, V36, P39
ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
AVANA APS, 1992, SUPERCOND SCI TECH, V5, P376
CIURCHEA D, 1996, SUPERCOND SCI TECH, V9, P88
FISHER DS, 1995, PHYS REV B, V51, P6411
GROSS R, 1993, INTERFACES HIGH TC S, P176
VOMHEDT B, 1994, PHYS REV B, V49, P9898
YE M, 1996, PHYSICA C, V258, P95
TC 0
PD NOV
PY 1996
VL 105
IS 3-4
BP 1053
EP 1059
UT ISI:A1996VX65200123
ER
--------------------------------------------------------------------------------
PT J
AU Pop, AV
Ilonca, G
Ciurchea, D
Rusu, M
Corega, C
Ilonca, M
Deltour, R
TI Effect of 3d element substitution on inter- and intragrain critical temperatures in (Bi,Pb):2223 system
SO CZECHOSLOVAK JOURNAL OF PHYSICS
AB The inter- and intragrain critical temperatures are differently affected by the natur and concentration of the 3d substituent (Fe,Ni,Zn) for Cu. Decrease of these temperatures is in agreement with the increase in residual resistivity.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
RP Pop, AV, UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR ILONCA G, 1994, PHYSICA C 2, V235, P1391
MAEDA A, 1990, PHYS REV B, V41, P4112
MARINO A, 1994, PHYSICA C 2, V235, P1425
POP AV, 1996, IN PRESS INT J MOD B, V10
UCHINOKURA K, 1989, PHYSICA C, V162, P981
TC 0
PY 1996
VL 46
SU Suppl. 3
BP 1305
EP 1306
UT ISI:A1996VL44000062
ER
--------------------------------------------------------------------------------
PT J
AU Ciurchea, D
Pop, AV
Gheorghiu, C
Furtuna, I
Todica, M
Dinu, A
Roth, M
TI Texture, morphology and deformation mechanisms in beta-transformed Zircaloy-4
SO JOURNAL OF NUCLEAR MATERIALS
AB The morphology of the beta(bcc) transformed Zircaloy-4 may be treated as a lenticular-twinned martensite. The texture is a consequence of the degeneration of the [0001](alpha), [10 (1) over bar 0](alpha) and [10 (1) over bar 1](alpha) directions into [110](beta) directions. The crystallographic mechanisms implied in the accommodation of the microscopic Bain strain are (10 (1) over bar 0)[11 (2) over bar 0] prism slip, (10 (1) over bar 2)[10 (1) over bar 1] twinning and (10 (1) over bar 1)[10 (1) over bar 2] twinning. This degeneration explains the 'parallel plate' and 'basketweave' morphologies observed by microscopy and the texture of the beta transformed tube. The macroscopic Bain strain was calculated and agrees with the dimensional measurements. The deformation mechanisms of beta transformed Zircaloy-4 are identified from the new texture and from deformation experiments as twinning and interplatelet glide. The interplatelet glide induces a fragile character of fracture in the 'parallel plate' morphology.
C1 INST NUCL RES,PITESTI 0300,ROMANIA.
RP Ciurchea, D, UNIV BABES BOLYAI,FAC PHYS,CLUJ NAPOCA 3400,ROMANIA.
CR ALECU M, 1988, THESIS IFIN BUCHARES
BOWLES JS, 1954, ACTA METALL, V2, P129
BUNGE HJ, 1969, MATH METHODEN TEXTUR
BURGERS WG, 1934, PHYSICA, V1, P563
CHARQUET D, 1987, ASTM STP, V939, P284
CHRISTIAN JW, 1974, PHYSICAL METALLURGY, P471
CIURCHEA D, 1985, J NUCL MATER, V131, P1
FELDMANN K, 1980, JINRP1180844
FELDMANN K, 1981, KRISTALL TECHN, V16, P1165
HADDAD RE, 1994, AM SOC TEST MATER, V1245, P559
HARDY DG, 1970, ASTM STP, V484, P215
HARDY DG, 1977, ASTM STP, V633, P98
HOLT RA, 1970, J NUCL MATER, V35, P322
HOLT RA, 1973, J NUCL MATER, V47, P262
HOLZER R, 1975, PHYSICAL METALLURGY
HSTINGS IJ, 1983, AECLMISC2502
HUNT CEL, 1980, J NCUL MAT, V92, P184
JUNG SH, 1989, J NUCL SCI TECHNOL, V26, P516
JUNG V, 1983, J APPL CRYSTALLOGR, V16, P535
KELLY A, 1970, CRYSTALLOGRAPHY CRYS, P313
KLUG HP, 1974, XRAY DIFFRACTION PRO
MARQUES FDS, 1982, J PHYS-PARIS, V12, P309
MUKHERJEE K, 1982, J PHYSIQUE, V12, P297
MURTY KL, 1994, ACTA METALL MATER, V42, P3653
MURTY KL, 1994, NUCL ENG DES, V148, P1
OKQVIST G, 1970, J NUCL MATER, V35, P316
PARTRIDGE PG, 1967, METALL REV, V12, P169
RAPPERPORT EJ, 1959, ACTA METALL, V7, P254
ROE RJ, 1965, J APPL PHYS, V36, P2024
SCHULZ LG, 1949, J APPL PHYS, V20, P1030
SMIRNOV V, 1973, COURS MATH SUPERIEUR, V3
TENCKHOFF E, 1980, VERFORMUNGSMECHANISM
VANGINNEKEN AJJ, 1952, ACTA CRYSTALLOGR, V5, P548
TC 4
PD JUL
PY 1996
VL 231
IS 1-2
BP 83
EP 91
UT ISI:A1996VH02200011
ER
--------------------------------------------------------------------------------
PT J
AU Pop, AV
Ilonca, G
Ciurchea, D
Ye, M
Geru, II
Kantser, VG
Pop, V
Todica, M
Deltour, R
TI Effect of Fe substitution on the magnetic and electrical properties of the (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca-2(Cu1-xFex)(3)O-y superconductor
SO JOURNAL OF ALLOYS AND COMPOUNDS
AB The partial substitution of Fe for Cu on the electrical and magnetic properties of (Bi1.6Pb0.4)(Sr1.8Ba0.2) Ca-2(Cu1-xFex)(3)O-y (0 less than or equal to x less than or equal to 0.05) has been investigated by electrical resistance, magnetic a.c. and static susceptibilities measurements. The superconducting transition temperature T-c decreases with increasing Fe concentration and the samples are characterized by a linear temperature dependence of the electrical resistance above 2T(c). The excess conductivity was analyzed. The inter- and intragrain critical temperatures are affected differently. Static susceptibility yielded the effective magnetic moments corresponding to the high spin state of Fe3+.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
MOLDOVA STATE UNIV,FAC PHYS,KISHINEV 277014,MOLDOVA.
INST PHYS APPL,KISHINEV 277028,MOLDOVA.
TECH UNIV,CLUJ NAPOCA 3400,ROMANIA.
RP Pop, AV, UNIV BABES BOLYAI,FAC PHYS,CLUJ NAPOCA 3400,ROMANIA.
CR ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
BAHTIA SN, 1994, PHYS REV B, V49, P12206
BAHTIA SN, 1994, PHYSICA C, V235, P1449
DIAZ A, 1995, J APPL PHYS, V77, P765
FINKELSTEIN AM, 1990, PHYSICA C, V168, P370
FOULKES JF, 1977, PHYS REV B, V15, P1395
GERU II, 1995, ROM REP PHYS, V47, P161
JUNOD A, 1988, PHYSICA C, V152, P485
LAWRENCE WE, 1970, 12TH P INT C LOW TEM, P361
LEPAGE Y, 1989, PHYS REV B, V40, P6810
LI Y, 1994, PHYSICA C 2, V235, P1247
MANIVANNAN V, 1991, PHYS REV B B, V43, P8686
MARINO A, 1994, PHYSICA C 2, V235, P1425
NUNEZ L, 1991, PHYS REV B, V44, P4526
POP AV, 1996, INT J MOD PHYS B, V10, P967
RAMESH R, 1990, J APPL PHYS, V67, P379
SAVITZKY A, 1964, ANAL CHEM, V36, P1627
TITTONEN I, 1990, PHYS REV B, V42, P4212
VOMHEDT B, 1994, PHYS REV B, V49, P9898
XIAO G, 1987, PHYS REV B, V35, P8782
TC 12
PD AUG 1
PY 1996
VL 241
IS 1-2
BP 116
EP 120
UT ISI:A1996VG43200019
ER
--------------------------------------------------------------------------------
PT J
AU Pop, AV
Ilonca, G
Ciurchea, D
Ye, M
Deltour, R
Geru, II
Kantser, VG
Konopko, LA
Geru, VI
TI Transport properties and ac susceptibilities of (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca-2(Cu1-xNix)(3)O-y superconductor
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB The effect of the partial substitution of Cu by Ni in the stabilized 108 K phase was investigated by electrical resistance and a.c. susceptibility measurements. Up to a Ni concentration x = 0.02 the bending of the R(T) curve above T-c can be described in the terms of the Lawrence-Doniach theory. The intergrain and intragrain critical transition temperatures decrease to Delta T-CG = 9 K and Delta T-j = 10.9 K respectively by the Ni substitution in the Cu-O pyramids.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
MOLDOVA STATE UNIV,FAC PHYS,KISHINEV 277014,MOLDOVA.
INST APPL PHYS,KISHINEV 277014,MOLDOVA.
RP Pop, AV, BABES BOLYAI UNIV,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
BAHTIA SN, 1994, PHYS REV B, V49, P12206
BAHTIA SN, 1994, PHYSICA C, V235, P1449
CHANDA B, 1994, SOLID STATE COMMUN, V89, P353
CIURCHEA D, 1996, IN PRESS SUPERCOND S
DIAZ A, 1995, J APPL PHYS, V77, P765
HALBRITTER J, 1993, PHYS REV B, V48, P9735
IVENS R, 1992, SUPERCOND SCI TECH, V5, P16
KULKARNI P, 1990, PHYSICA C, V168, P530
LAWRENCE WE, 1970, 12TH P INT C LOW TEM, P361
LIU HK, 1988, PHYSICA C, V157, P93
MAEDA A, 1990, PHYS REV B, V41, P4112
MAEDA H, 1988, JPN J APPL PHYS PT 2, V27, L209
MAENO Y, 1987, NATURE, V328, P512
MARINO A, 1994, PHYSICA C 2, V235, P1425
MICHEL C, 1987, Z PHYS B CON MAT, V68, P421
NATSUME H, 1991, JPN J APPL PHYS PT 2, V30, L461
POP AV, 1995, INT J MOD PHYS B, V9, P695
SAVITZKY A, 1964, ANAL CHEM, V36, P1627
VOMHEDT B, 1994, PHYS REV B, V49, P9898
WEIGANG G, 1989, Z PHYS B CON MAT, V77, P11
WINZER K, 1991, Z PHYS B CON MAT, V82, P317
ZHIGUIANG M, 1993, PHYS REV B, V48, P14427
TC 10
PD APR 10
PY 1996
VL 10
IS 8
BP 967
EP 976
UT ISI:A1996UH50300003
ER
--------------------------------------------------------------------------------
PT J
AU Ciurchea, D
Pop, AV
Cozar, O
Ilonca, G
Geru, VI
Pop, V
Konopko, LA
TI Statistical representation of the excess conductivity in a Bi-Sr-Ca-Cu-O superconductor
SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY
AB The onset of superconductivity may be described by the product of a Gaussian with a Student distribution. The excess conductivity properties of many specimens are numerically fitted and prove the accuracy of this model. The number of degrees of freedom yielded by the Student distribution corresponds to the number of independent variants of percolation of the Cooper pairs above T-cmf. This number depends linearly on the type of 3d substituents of Cu (Zn, Fe, Ni).
C1 TECH UNIV,DEPT PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
INST APPL PHYS,KISHINEV 277028,MOLDOVA.
RP Ciurchea, D, BABES BOLYAI UNIV,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR 1990, TABLE PERIODIC PROPE
ARONOV AG, 1995, PHYS REV B, V51, P3880
ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
AUSLOOS M, 1988, MOD PHYS LETT B, V2, P1319
BARADUC C, 1995, PHYSICA C, V248, P138
BHATIA SN, 1994, PHYS REV B, V49, P12206
CIURCHEA D, 1995, PRELUCRAREA DATELOR
ESSAM JW, 1980, REP PROG PHYS, V43, P835
FEINBERG D, 1994, PHYS REV B, V49, P6285
FISHER DS, 1995, PHYS REV B, V51, P6411
HALBRITTER J, 1993, PHYS REV B, V48, P9735
LANG W, 1994, PHYSICA C 2, V235, P1447
LAWRENCE WE, 1970, 12TH P INT C LOW TEM, P361
MAEDA A, 1990, PHYS REV B, V41, P4112
MAKI K, 1968, PROG THEOR PHYS, V39, P897
MAKI K, 1968, PROG THEOR PHYS, V40, P193
MOU CY, 1995, PHYS REV B, V51, P6575
NATSUME H, 1991, JPN J APPL PHYS PT 2, V30, L461
POP AV, 1994, SUPERCOND SCI TECH, V7, P558
POP AV, 1995, INT J MOD PHYS B, V9, P695
PREDHAM AK, 1994, PHYS REV B, V50, P7180
PRESS WH, 1988, NUMERICAL RECIPES
SAVITZKY A, 1964, ANAL CHEM, V36, P1627
THOMPSON RS, 1970, PHYS REV B, V1, P327
TIRON M, 1976, PRELUCRAREA STATISTI
UCHINOKURA K, 1989, PHYSICA C, V162, P981
VEIRA JA, 1989, PHYSICA C, V159, P468
ZHIQUIANG M, 1993, PHYS REV B, V48, P14427
TC 6
PD FEB
PY 1996
VL 9
IS 2
BP 88
EP 92
UT ISI:A1996TW50500004
ER
--------------------------------------------------------------------------------
PT J
AU ILONCA, G
POP, AV
MEHBOD, M
DEBRUE, G
CIURCHEA, D
DELTOUR, R
TI TRANSPORT-PROPERTIES OF YBA2(CU1-XZNX)(3)O-7-DELTA FILMS
SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY
AB Zn doped epitaxial films of YBa2(Cu1-xZnx)(3)O-7-delta with 0 less than or equal to x less than or equal to 0.06 have been prepared by high-oxygen-pressure d.c. sputtering from stoichiometric targets on MgO substrate. The temperature dependences of the transport properties were investigated by electrical resistivity and Hall effect measurements. The transition temperatures and the Hall concentration per unit cell decrease with increasing Zn content. The temperature dependence of the Hall density n(H) and T-2 dependence of the inverse mobility shows an anomaly around 250 K.
C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM.
RP ILONCA, G, BABES BOLYAI UNIV,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR 1989, PHYSICA C, V162
ANDERSON PW, 1991, PHYS REV LETT, V67, P2092
ANDERSON PW, 1991, PHYSICA C, V185, P11
CARRINGTON A, 1993, PHYS REV B, V48, P13051
CHIEN TR, 1991, PHYS REV B B, V43, P6242
CHIEN TR, 1991, PHYS REV LETT, V67, P2088
CLAYHOLD J, 1989, PHYS REV B, V39, P7324
COOPER JR, 1991, SUPERCOND SCI TECH, V4, S277
FUKUYAMA H, 1984, PHYSICA B C, V126, B306
HOPFENGARTNER R, 1993, PHYS REV B, V47, P5992
ILONCA G, 1993, PHYS REV B, V47, P15265
JONES EC, 1993, PHYS REV B, V47, P8986
KREMER RK, 1992, Z PHYS B, V86, P319
MARTIN S, 1988, PHYS REV LETT, V60, P2194
MEHBOD M, 1988, PHYS REV B, V38, P1181
MEHRING M, 1993, PHYSICA SCRIPTA T, V49, P124
NIZHNYAKOV V, 1988, PHYSICA C, V156, P655
POP AV, 1994, SUPERCOND SCI TECH, V7, P558
POP AV, 1995, INT J MOD PHYS B, V10
RAVEN MS, 1995, PHYS REV B, V51, P561
SPECKMANN M, 1992, PHYS REV B, V45, P8189
TACHIKI M, PHYSICS C, V185
TAMEGAI T, 1991, PHYS REV B, V44, P10167
VONHEDT B, 1994, PHYS REV B, V49, P9898
WALKER DJC, 1994, PHYSICA C 2, V235, P1335
WATANABE T, 1994, PHYSICA C, V235, P1495
WESTERHOLT K, 1989, PHYS REV B, V39, P11680
WUYTS B, 1993, PHYS REV B, V47, P5512
WUYTS B, 1994, PHYSICA C, V235, P1369
ZAGOULAEV S, 1994, PHYSICA C 2, V235, P1333
TC 11
PD AUG
PY 1995
VL 8
IS 8
BP 642
EP 646
UT ISI:A1995RP39200007
ER
--------------------------------------------------------------------------------
PT J
AU POP, AV
ILONCA, G
CIURCHEA, D
DARABONT, A
BORODI, G
POP, V
GIURGIU, LV
TI MAGNETIC STUDIES ON MN-SUBSTITUTED Y-BA-CU-O
SO JOURNAL OF ALLOYS AND COMPOUNDS
AB Magnetic d.c. and a.c. susceptibility and lattice constant measurements were performed in the normal state of YBa2Cu3-xMnxO7-delta with Mn concentrations x=0.075, 0.15, 0.2, 0.25 and 0.3. The orthorhombic structure is preserved throughout the substitution range and some amount of impurity phases were evidenced in the samples with x>0.2. The inter- and intragrain properties from a.c. susceptibility measurements show different behaviour above and below the x=0.2 Mn in the YBCO. The measurements of the d.c. susceptibility were analysed using a Curie-Weiss law with a temperature-independent background. The effective magnetic moment obtained per Mn atom, p(Mu)=3.29 mu(B), suggests the presence of a 4+ oxidation state. The variation of the Curie paramagnetic temperature B for different x is associated with an antiferromagnetic exchange interaction between the Mn ions. A regular trend of p(effect)(2) and T-c as a function of x suggest that below x=0.2 Mn ions are substituted in the Cu(1R) positions.
C1 INST ISOTOPE & MOLEC TECHNOL INST,R-3400 CLUJ NAPOCA,ROMANIA.
TECH UNIV CLUJ,DEPT PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
RP POP, AV, UNIV BABES BOLYAI,DEPT PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR CAVA RT, 1987, PHYS REV LETT, P1676
JARDIM RF, 1988, PHYS REV B, V38, P4580
JARDIM RF, 1989, PHYSICA C, V159, P306
KALLIAS G, 1992, SUPERCOND SCI TECH, V5, P56
MOTO A, 1990, SUPERCOND SCI TECH, V3, P579
MURALIDHARAN PU, 1991, JPN J APPL PHYS PT 1, V30, P280
NUNEZ L, 1991, PHYS REV B, V44, P4526
PADALIA BD, 1992, J PHYS-CONDENS MAT, V4, P6865
POP AV, IN PRESS ROMANIAN RE
SAINI NL, 1992, INT J MOD PHYS B, V6, P3515
SAINI NL, 1992, SOLID STATE COMMUN, V82, P895
ULLMANN B, 1990, PHYSICA C, V170, P71
YANG Y, 1989, SOLID STATE COMMUN, V65, P585
TC 0
PD MAY 15
PY 1995
VL 223
IS 1
BP 56
EP 59
UT ISI:A1995RD47000015
ER
--------------------------------------------------------------------------------
PT J
AU POP, AV
ILONCA, GH
CIURCHEA, D
POP, V
KONOPKO, LA
GERU, II
TODICA, M
IONCU, V
TI PARACONDUCTIVITY AND HALL-EFFECT MEASUREMENTS IN THE SUPERCONDUCTING (BIPB)(2)(SRBA)(2)CA-2(CU1-XCX)(3)O-Y
SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B
AB The effect of the Cu substitution by Cc in the ''2223'' superconductor was studied by resistivity and Hall effect measurements. The excess conductivity was analyzed by using the linear and Zou-Anderson extrapolation methods on the electrical resistivity. A crossover temperature is observed only for the x = 0 sample. The sheet hole concentration per Cu-site, n(H)V(cell) is found to vary linearly with the temperature for all Cr doped samples in the 170-265 K temperature range. Deviations from linearity in the T-2 dependence of the inverse Hall mobility above 250 K were evidenced.
C1 TECH UNIV CLUJ NAPOCA,DEPT PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
INST APPL PHYS,KISHINEV 277028,MOLDOVA.
MOLDOVA STATE UNIV,FAC PHYS,KISHINEV 277014,MOLDOVA.
RP POP, AV, BABES BOLYAI UNIV,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR ANDERSON PW, 1988, PHYS REV LETT, V60, P132
ANDERSON PW, 1991, PHYSICA C, V185, P11
AUSLOOS M, 1988, MOD PHYS LETT B, V2, P1319
BOULESTEIX C, 1994, INT C M2 HTSC GRENOB, V4, P58
CLAYHOLD J, 1989, PHYS REV B, V39, P7320
FURRER A, 1994, INT C M2 HTSC GRENOB, P27
GRADER GS, 1988, PHYS REV B, V48, P844
HALBRITTER J, 1993, PHYS REV B, V48, P9735
ILONCA G, 1993, PHYS REV B, V47, P15265
ILONCA G, 1994, PHYSICA C 2, V235, P1391
KUBO Y, 1989, 2ND P INT S SUP TSUK
LABDI S, 1993, SOLID STATE COMMUN, V85, P491
LAWRENCE WE, 1971, 12TH P INT C LOW TEM, P361
LIU HK, 1988, PHYSICA C, V157, P93
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MAEDA A, 1990, PHYS REV B, V41, P6418
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POP AV, 1994, ICMMM AUG
POP AV, 1994, IN PRESS BALKAN PHYS
POP AV, 1994, SUPERCOND SCI TECH, V7, P558
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VIRET M, 1994, PHYS REV B, V49, P3457
XIA TR, 1988, PHYS REV B, V47, P118
ZHIQUIANG M, 1993, PHYS REV B, V48, P14427
TC 6
PD MAR 15
PY 1995
VL 9
IS 6
BP 695
EP 705
UT ISI:A1995QZ85700004
ER
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PT J
AU POP, AV
CIURCHEA, D
POP, V
COSMA, I
ILONCA, G
TI FLUCTUATION CONDUCTIVITY AND HALL-EFFECT MEASUREMENTS IN Y1-XGDXBA2CU3O7-DELTA SUPERCONDUCTOR
SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY
AB Polycrystalline sintered samples of Y1-xGdxBa2Cu3O7-delta have been prepared and their excess conductivity DELTAsigma(T) has been analysed. The fluctuation conductivity shows dimensional cross-over, and the 3D character is well described by the Aslamasov-Larkin contribution. By using these data and the dimensional cross-over temperature T0, the interlayer coherence length xi(c)(0) is evaluated. The temperature dependence of the Hall number and the T2 dependence of the inverse Hall mobility show an anomaly above 220 K and deviations from linearity at temperatures below 150 K in the fluctuation conductivity regime.
C1 TECH UNIV CLUJ NAPOCA,DEPT PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
RP POP, AV, BABES BOLYAI UNIV,FAC PHYS,R-3400 CLUJ NAPOCA,ROMANIA.
CR ALLOUL H, 1991, PHYS REV LETT, V67, P3140
ANDERSON PW, 1988, PHYS REV LETT, V60, P132
ASHKENAZI J, 1993, UNPUB J SUPERCOND
ASLAMAZOV LG, 1968, PHYS LETT A, V26, P238
BAHTIA SN, 1991, PHYSICA C, V185, P1845
CHIEN TR, 1991, PHYS REV B B, V43, P6242
CLAYHOLD J, 1989, PHYS REV B, V39, P7324
COOPER JR, 1991, PHYS REV B, V44, P12086
FREITAS PP, 1987, PHYS REV B, V36, P833
FRIEDMANN TA, 1990, PHYS REV B, V42, P6217
GINSBERG DM, 1993, PHYS REV B, V47, P12167
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HENTSCH F, 1992, Z PHYS B, V86, P319
HIZHNYAKOV V, 1988, PHYSICA C, V156, P655
HIZHNYAKOV V, 1989, PHYSICA C, V161, P435
HUNDLEY MF, 1990, PHYS REV B, V41, P4062
ILONCA G, 1993, PHYS REV B, V47, P15265
LAWRENCE WE, 1971, 12TH P INT C LOW TEM, P361
LEPAGE Y, 1987, PHYS REV B, V36, P3617
LORAM JW, 1991, PHYSICA C, V185, P1751
MAKI K, 1989, PHYS REV B, V39, P2767
MANDAL P, 1990, PHYSICA C, V169, P43
MATSUDA Y, 1988, SOLID STATE COMMUN, V68, P103
MATSUDA Y, 1989, PHYS REV B, V40, P5176
OH B, 1988, PHYS REV B, V37, P7861
ONG NP, 1991, PHYSICA C, V185, P34
PADMANABAN VPN, 1993, PHYSICA C, V208, P263
RICE JP, 1991, PHYSICA C, V185, P1853
TAMEGAI T, 1991, PHYS REV B, V44, P10167
VEIRA JA, 1989, PHYSICA C, V159, P468
VEIRA JA, 1990, PHYSICA B, V165, P1367
VIDAL F, 1988, SOLID STATE COMMUN, V66, P421
WANG ZZ, 1987, PHYS REV B, V36, P7222
TC 3
PD AUG
PY 1994
VL 7
IS 8
BP 558
EP 562
UT ISI:A1994PB70900004
ER
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PT J
AU CALU, N
SANDU, I
BERDAN, I
LUPUTIU, M
CIURCHEA, D
CALU, M
TI COLLOIDAL GRAPHITE-WATER DISPERSE SYSTEMS .2. OBTAINING AND DETERMINING OF SEMIGRAPHITIZED CARBON-BLACK WATER DISPERSE SYSTEMS
SO REVISTA DE CHIMIE
RP CALU, N, INST POLITECH IASI,FAC TEHNOL CHIM,IASI,ROMANIA.
TC 0
PD APR
PY 1987
VL 38
IS 4
BP 307
EP 311
UT ISI:A1987H871700004
ER
--------------------------------------------------------------------------------
PT J
AU SANDU, I
CALU, N
CIURCHEA, D
BERDAN, I
CALU, M
FURTUNA, I
TI WATER-COLLOIDAL GRAPHITE DISPERSE SYSTEMS .1. DESCRIPTION OF THE COMPONENTS
SO REVISTA DE CHIMIE
RP SANDU, I, FAC TEHNOL CHIM IASI,INST POLITEH,IASI,ROMANIA.
TC 0
PD NOV
PY 1986
VL 37
IS 11
BP 968
EP 974
UT ISI:A1986F783700007
ER
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PT J
AU CIURCHEA, D
TI TEXTURE INDUCED ANISOTROPY IN ZIRCALOY-4 TUBES
SO JOURNAL OF NUCLEAR MATERIALS
RP CIURCHEA, D, INST NUCL POWER REACTORS,POB 78,R-0300 PITESTI,ROMANIA.
CR BEAUREGARD RJ, 1977, 4TH T SMIRT C SAN FR
BUCKLEY SN, 1962, IRRADIATION GROWTH P, P413
BUNGE HJ, 1969, MATH METHODEN TEXTUR
CALNAN EA, 1951, PHILOS MAG, V42, P919
CATLIN WR, 1977, J NUCL MATER, V68, P345
CIURCHEA D, UNPUB
COLEMAN CE, 1975, PHYSICAL METALLURGY, P302
COUTERNE JC, 1979, J NUCL MATER, V79, P58
DRESSLER G, 1972, ASTMSTP551
DRESSLER G, 1972, CAN METALL Q, V11, P177
DRESSLER G, 1973, 2ND SMIRT C BERL
EISENBERG MA, 1980, J NUCL MATER, V88, P138
FISHER ES, 1961, J NUCL MATER, V4, P311
FISHER ES, 1964, PHYS REV, V135, A482
GHEATA V, 1982, OCT C NAT FIZ BUCH R, P322
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HOLT RA, 1979, ACTA METALL, V27, P1319
HOLZER R, 1975, PHYSICAL METALLURGY, P461
HUNT CEL, 1980, J NCUL MAT, V92, P184
IBRAHIM EF, 1981, J NUCL MATER, V101, P1
IBRAHIM EF, 1981, J NUCL MATER, V102, P214
KALLSTROM K, 1969, J NUCL MATER, V31, P111
KEARNS JJ, 1965, WAPDTM472 REP
LUCAS GE, 1975, J NUCL MATER, V55, P264
MERKLE JG, 1966, ORNLTM1553 REP
NAKATSUKA M, 1981, NUCL ENG DES, V65, P103
NORTHWOOD DO, 1975, J NUCL MATER, V55, P299
OLDBERG S, 1979, ASTM STP681, P370
RAPPERPORT EJ, 1959, ACTA METALL, V7, P254
ROE RJ, 1965, J APPL PHYS, V36, P2024
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ROSINGER HE, 1979, J NUCL MATER, V79, P170
SCHULZ LG, 1949, J APPL PHYS, V20, P1030
SIROTIN II, 1981, FIZICA CRISTALELOR
VONMISES R, 1928, Z ANGEW MATH MECH, V8, P161
TC 1
PY 1985
VL 131
IS 1
BP 1
EP 10
UT ISI:A1985AHF6400001
ER
--------------------------------------------------------------------------------
PT J
AU BARB, D
MORARIU, M
DIAMANDESCU, L
ZNAMIROVSCHI, V
CIURCHEA, D
MOTIU, A
TI MOSSBAUER STUDIES ON MOCI (ROMANIA) METEORITE
SO ANNALES DE GEOPHYSIQUE
C1 UNIV BABES BOLYAI,DEPT BIOL GEOG & GEOL ENGN,R-3400 CLUJ,ROMANIA.
UNIV BABES BOLYAI,DEPT PHYS,R-3400 CLUJ,ROMANIA.
RP BARB, D, INST PHYS & TECHNOL MAT,POB MG6,R-79900 BUCHAREST,ROMANIA.
CR BANCROFT GM, 1967, GEOCHIM COSMOCHIM AC, V31, P2219
BANCROFT GM, 1968, GEOCHIM COSMOCHIM AC, V32, P547
BARB D, 1972, MOSSBAUER EFFECT ITS
FARRINGTON OC, 1915, METEORITES
GIBB TC, 1972, MOSSBAUER SPECTROSCO
HAIDUC I, 1977, NCST269 RAPP
HAVENS WW, 1951, PHYS REV, V83, P1123
HERR W, 1969, METEORITE RES
JOHNSON CE, 1963, P PHYS SOC LOND, V81, P1079
JOHNSTON CE, 1961, PHYS REV LETT, V6, P450
KEDING X, 1978, GEOCHEMICA, P157
LANDAU L, 1968, PHYSIQUE STATISTIQUE
MADDOCK AG, 1972, IAEA VIENNA, P329
MALYSHEVA TV, 1973, GEOCHIMIJA, P1328
MALYSHEVA TV, 1973, P INT C MOSSBAUER 2, P385
MALYSHEVA TV, 1976, GEOKHIMIYA, P949
MALYSHEVA TV, 1977, P INT C MOSSBAUER SP, V1, P321
MASON E, 1965, METEORITES
PRIOR GT, 1953, CATALOGUE METEORITES
SPRENKELSEGEL EL, 1964, GEOCHIM COSMOCHIM AC, V28, P1913
STANCIU V, 1943, REV MUZ MIN GEOL U C, V7, P121
ZEMCIK T, 1976, J PHYS, V37, P833
ZNAMIROVSCHI V, 1981, REV ROUM PHYS, V26, P745
TC 1
PY 1982
VL 38
IS 6
BP 875
EP 879
UT ISI:A1982RC50100016
ER
--------------------------------------------------------------------------------
PT J
AU BARB, D
DIAMANDESCU, L
ZNAMIROVSCHI, V
CIURCHEA, D
SEMENIUC, R
TI MOSSBAUER-SPECTROSCOPY INVESTIGATIONS OF IRON IN SOME PENTACOORDINATE COMPLEXES
SO REVUE ROUMAINE DE CHIMIE
C1 UNIV BABES BOLYAI,FAC PHYS,R-3400 CLUJ,ROMANIA.
RP BARB, D, INST PHYS & TECHNOL MAT,POB 5207,BUCHAREST,ROMANIA.
CR BARB D, 1972, EFECTUL MOSSBAUER AP
DANON J, 1966, APPLICATIONS MOSS 50, P89
FURLANI C, 1968, COORDIN CHEM REV, V3, P141
SHARMA RK, 1974, J INORG NUCL CHEM, V36, P1172
TC 1
PY 1980
VL 25
IS 11-1
BP 1485
EP 1487
UT ISI:A1980LF26700005
ER
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Prof.Dr. D. Ciurchea
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ISI abstracts of the ISI papers (long file)
