Interpretation of the anomalous field-cooled-magnetization behavior of high-temperature granular superconductors at low magnetic field

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.1258· OSTI ID:6424580

Chen, F H ^[1]; Tai, M F ^[2]; Horng, W C; Tseng, T Y ^[1]

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1. Department of Electronics Engineering and Institute of Electronics, National Chiao-Tung University, Hsinchu, Taiwan (Taiwan, Province of China)
2. Telecommunication Laboratories, Ministry of Transportation Communication, P.O. Box 71, Chung-Li, Taiwan (Taiwan, Province of China)

The field-cooled magnetization of high-[ital T][sub [ital c]] superconducting ceramics measured in low magnetic fields has exhibited an unusual phenomenon, i.e., the diamagnetic signal initially increases with a decrease in temperature but reaches a maximum at temperature [ital T][sub [ital d]] and subsequently decreases with a decrease in temperature. In some samples the signal could even transform inversely into a paramagnetic regime once the sample was cooled below a temperature [ital T][sub [ital p]], provided the applied field was sufficiently small. This phenomenon has been observed in various high-[ital T][sub [ital c]] cuprates and been explained with different viewpoints. An alternative theoretical model was proposed in this work to account for these phenomena. The anomalous magnetization behavior in the present model was demonstrated to be a superposition of the diamagnetic signal, which occurs as a result of the intragranular shielding currents, and the paramagnetic signal, due to the induction of the intergranular component induced by these currents. The intergranular effect was demonstrated by this model to exist in granular superconductors. This intergranular effect would therefore be considered in evaluating the volume fraction of superconductivity for the samples from the Meissner signal, in particular, at a low magnetic field.

• OSTI ID: 6424580
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:2; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COOLING
COPPER COMPOUNDS
CUPRATES
DIAMAGNETISM
GRANULAR MATERIALS
HIGH-TC SUPERCONDUCTORS
MAGNETISM
MAGNETIZATION
MATERIALS
OXYGEN COMPOUNDS
PARAMAGNETISM
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS