AC susceptibility and intergranular critical current density study in pure and Ag doped (La1−xYx)2Ba2CaCu5Oz superconductors

2006 ◽  
Vol 138 (8) ◽  
pp. 377-381 ◽  
Author(s):  
P.K. Nayak ◽  
S. Ravi
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Ac Susceptibility ◽  
Density Study ◽  
Intergranular Critical Current Density

INTERGRANULAR PROPERTIES OF (Y1-x-yZrxCay)Ba2Cu3O7-δ COMPOUNDS

1999 ◽  
Vol 13 (13) ◽  
pp. 1645-1654 ◽  
Author(s):  
I. GR. DEAC ◽  
E. BURZO ◽  
A. V. POP ◽  
V. POP ◽  
R. TETEAN ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Ac Susceptibility ◽  
Temperature Dependent ◽  
Susceptibility Data ◽  
Dc Magnetic Field ◽  
Complex Susceptibility ◽  
Granular Superconductors ◽  
Intergranular Critical Current Density

The intergranular properties of ( Y 1-x-y Zr x Ca y) Ba 2 Cu 3 O 7-δ ceramics were studies by using temperature-dependent ac susceptibility measurements at zero dc magnetic field. The intergranular critical current density was determined from ac susceptibility data by varying the field amplitude H ac . From the imaginary part of the complex susceptibility, χ″(T), we have determined the temperature dependence of the critical current density by using the Bean's model. The ac field dependencies of the intergrain χ″-peak temperatures T p are linear and agree with Müller critical state model. The results were analyzed in terms of superconductor-insulator-superconductor (SIS)-and superconductor-normal-superconductor (SNS)-type models for granular superconductors.

AC SUSCEPTIBILITY OF YBCO SUPERCONDUCTING THIN FILMS

2006 ◽  
Vol 20 (15) ◽  
pp. 923-929
Author(s):  
C. SBÂRCIOG ◽  
T. R. REDAC ◽  
I. GR. DEAC
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Ac Susceptibility ◽  
Superconducting Thin Films ◽  
Superconducting Transition ◽  
Susceptibility Data ◽  
Complex Susceptibility ◽  
Intergranular Critical Current Density

Ca -doped (x = 0.00, 0.07 and 0.20) epitaxial Y 1-x Ca x Ba 2 Cu 3 O 7-δ thin films were prepared on SrTiO 3 (100) by PLD technique. The superconducting transition temperature is found to decrease with increasing Ca content. The AC-susceptibility data were used to determine the intergranular critical current density, when varying the field amplitude H AC . The temperature dependence of critical current density was determined from the imaginary part of the complex susceptibility, χ′′(T), using Xing's relation. The results were analyzed in terms of superconductor-insulator-superconductor (SIS) and superconductor-normal-superconductor (SNS) type models.

ANOMALOUS INCREASE OF THE TRANSPORT AND INDUCTIVE CRITICAL CURRENT DENSITY DUE TO LOW DC-FIELD COOLING IN SINTERED RBa2Cu3O7−x HIGH Tc SUPERCONDUCTORS

1991 ◽  
Vol 05 (26) ◽  
pp. 1727-1733
Author(s):  
T. PUIG ◽  
M. PONT ◽  
J.S. MUÑOZ
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Ac Susceptibility ◽  
Transport Critical Current Density ◽  
Zero Field ◽  
High Tc ◽  
Current Densities ◽  
Magnetic Flux Pinning ◽  
Intergranular Critical Current Density

The transport critical current density of bulk sintered samples of RBa2Cu3O7−x with R=Y, Gd, Ho, and Er has been determined at 77 K from I–V curves at different applied dc-magnetic fields (0≤H≤20 Oe), also the ac-susceptibility as a function of ac-field amplitude has been measured with a superimposed dc-magnetic field from 0 to 30 Oe at 77 K. The transport and magnetic (inductive) critical current densities, are clearly larger in field cooled samples than in zero field cooled samples. Likewise, the degree of shielding as determined from the ac-susceptibility measurements is larger for field cooled samples than for zero field cooled. This anomalous behaviour can be explained in terms of the magnetic flux pinning present in the grains when the sample is field cooled, which leads to a decrease in the magnetic induction of the intergrain region and therefore to a higher intergranular critical current density compared to a zero field cooled sample.

Perpendicular ac susceptibility and critical current density of distant superconducting twin films

2011 ◽  
Vol 24 (7) ◽  
pp. 075004 ◽  
Author(s):  
D-X Chen ◽  
G Via ◽  
C Navau ◽  
N Del-Valle ◽  
A Sanchez ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Ac Susceptibility

The Fe Influence on the Vortex Response to the AC Field in Bulk (Bi, Pb):2223 Superconductor

1998 ◽  
Vol 12 (27) ◽  
pp. 1117-1124 ◽  
Author(s):  
A. V. Pop
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Critical State ◽  
Ac Susceptibility ◽  
Field Amplitude ◽  
Critical State Model ◽  
Pinning Force ◽  
Fast Decrease ◽  
Ac Field

The effect of Fe 3+ ions on the inter- and intragranular Tp and Tg temperatures of the imaginary peaks of the AC susceptibility has been studied for a (Bi, Pb):2223 superconductor. The linear dependencies of Tp and Tg as a function of AC field amplitude agree with Muller critical state model. The Fe 3+ ions induced a fast decrease of inter and intragranular pinning force densities. The intergrain critical current density J cj calculated from χ″(T) curve is lower in x=0.02 Fe doped sample than in x=0.00 sample. J cj (T) dependence near Tc agrees with the assumption of SNS intergrain junctions.

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