NUMERICAL CALCULATIONS OF IMAGINARY SUSCEPTIBILITY IN THE INTERGRAIN REGION OF GRANULAR SUPERCONDUCTORS
1989; World Scientific; Volume: 03; Issue: 15 Linguagem: Inglês
10.1142/s0217984989001783
ISSN1793-6640
AutoresP.M. van den Berg, Gregory Kozlowski,
Tópico(s)Rare-earth and actinide compounds
ResumoUsing a critical state model for the intergrain critical current density (J c ) of a granular superconductor in which the grains are separated by Josephson junction type weak links, numerical calculations of the imaginary part of the complex susceptibility (χ″) and the ac losses (W) are performed. The dependences of the imaginary susceptibility on the amplitude of the external magnetic field (H ac ), grain size (R g ), barrier width (d), lower critical field (H cl ), normal resistivity of the junction (ρ j ) and temperature (T) are discussed. We also comment on a minimum in the hysteretic ac losses when a constant magnetic field (H dc ) is superimposed on the alternating field. Some comparison with experimental data is made.
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