Abstract
Single-phase tetragonal (La1-xCax)(Ba1.75-xLa0.25+x)Cu3 O7+d polycrystals with the composition range 0.1≤x≤1.0 were synthesized by the amorphous metal-complex method. The fundamental and the higher-harmonic complex susceptibilities χn = χn′-iχn″ (n = 1, 2, 3, 5, and 7) were measured by means of Hartshorn bridge. The ac-magnetic field superimposed on the earth's field was applied to the specimen. We observed nonzero values of χn for all n in the temperature range of the superconducting transition. The observed χn-T curves were analyzed by the Kim-Anderson critical-state model. We found that the pinning force density increases up to x = 0.5 and decreases over x = 0.5 with increasing the Ca content x, and is proportional to two kinds of the power of the elemental pinning force.
Original language | English |
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Pages (from-to) | 324-328 |
Number of pages | 5 |
Journal | Physica C: Superconductivity and its applications |
Volume | 378-381 |
Issue number | PART 1 |
DOIs | |
Publication status | Published - 2002 Oct 1 |
Externally published | Yes |
Keywords
- Ca substitution
- Harmonic susceptibilities
- La-based cuprates
- Pinning force
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering