Fluctuation-induced excess conductivity in the compounds CaREBaCu3O7?y
(RE=La and Sm) |
| |
| Authors: | H Krishnan R Srinivasan V Sankaranarayanan C K Subramaniam G V Subba Rao |
| |
| Affiliation: | (1) Materials Science Research Centre, Department of Physics, Indian Institute of Technology, 600 036 Madras, India |
| |
| Abstract: | The compounds CaREBaCu3O7−y
(RE=La and Sm) are tetragonal at room temperature withT
c
between 60 and 70 K. The single-phase compounds were prepared by solid-state reaction. The resistivity was measured by a
four-probe technique in a continuous flow cryostat with the temperature being controlled to an accuracy of 10 mK. The resistivity
vs temperature showed a break in slope around 180 K in CaLaBaCu3O7−y
and around 220 K in CaSmBaCu3O7−y
. The results were analysed for fluctuation conductivity from 180 K downwards. A plot of dρ/dT vsT showed a sharp peak atT
m
=69·69 K for La compound and 66·00 K for the Sm compound. Detailed analysis of the resistivity in the regionT
on to 180 K was carried out using the procedure due to Veira and Vidal. The results are discussed in this paper. |
| |
| Keywords: | HighT c superconductors CaREBaCu3O7− y fluctuation excess conductivity |
| 本文献已被 SpringerLink 等数据库收录！ |
