Pv. Patanjali et al., Field induced microwave absorption in melt textured and sintered high T-c superconductors, SUPERCOND S, 12(10), 1999, pp. 676-681
Low and high field dependent microwave absorption is studied in various sin
tered and melt textured HTSs. The low field loss is found to originate from
weak links and the high field loss is due to thermally assisted flux flow.
Melt textured superconductors are found to be best suited for low field de
vice applications due to the drastic reduction in low field induced loss wh
en compared to sintered samples. Melt textured superconductors with 211 inc
lusions are found to show reduced high field losses due to pinning of field
at the secondary defects created by 211 particulates. Various parameters o
f the critical state such as J(c) and the pinning force constant, K-x, are
determined from the microwave absorption study.