Effect of Hafnium Impurities on the Magnetoresistance of YBa2Cu3O7-δ

• Published in: Journal of low temperature physics Vol. 186; no. 3-4; pp. 285 - 293
• Main Authors: Savich, S. V., Samoylov, A. V., Kamchatnaya, S. N., Goulatis, I. L., Vovk, R. V., Chroneos, A., Solovjov, A. L., Omelchenko, L. V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-02-2017
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Physics; Physics and Astronomy; Excess conductivity; ceramic; 2D–3D crossover; Hf impurities; Pinning; Coherent length
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-016-1703-9

In the present study, we investigate the influence of the hafnium (Hf) impurities on the magnetoresistance of
YBa
2
Cu
3
O
7
-
δ
ceramic samples in the temperature interval of the transition to the superconducting state in constant magnetic field up to 12 T. The cause of the appearance of low- temperature “tails” (paracoherent transitions) on the resistive transitions, corresponding to different phase regimes of the vortex matter state is discussed. At temperatures higher than the critical temperature (
T
>
T
c
)
, the temperature dependence of the excess paraconductivity can be described within the Aslamazov–Larkin theoretical model of the fluctuation conductivity for layered superconductors.