Structural, Electrical and Magnetic Properties of (Y1–yCay)Ba2Cu3–x NixO7–δ Ceramics

  1. Prof. Dr. G. Müller
  1. Iosif Gr. Deac,
  2. Emil Burzo,
  3. Viorel Pop and
  4. Romulus Tetean

Published Online: 27 APR 2006

DOI: 10.1002/3527607293.ch41

Ceramics - Processing, Reliability, Tribology and Wear, Volume 12

Ceramics - Processing, Reliability, Tribology and Wear, Volume 12

How to Cite

Deac, I. Gr., Burzo, E., Pop, V. and Tetean, R. (2000) Structural, Electrical and Magnetic Properties of (Y1–yCay)Ba2Cu3–x NixO7–δ Ceramics, in Ceramics - Processing, Reliability, Tribology and Wear, Volume 12 (ed G. Müller), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527607293.ch41

Editor Information

  1. Fraunhofer-Institut für Silicatforschung, Neunerplatz 2, 97082 Würzburg, Germany

Author Information

  1. Faculty of Physics, “Babes-Bolyai” University, 3400 Cluj-Napoca, Romania

Publication History

  1. Published Online: 27 APR 2006
  2. Published Print: 27 JUN 2000

Book Series:

  1. EUROMAT 99

ISBN Information

Print ISBN: 9783527301942

Online ISBN: 9783527607297

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Keywords:

  • (Y1-yCay)Ba2Cu3-x NixO7-δ ceramics;
  • structural;
  • electrical;
  • magnetic properties

Summary

Polycrystalline samples of nominal composition (Y1–yCay)Ba2Cu3–x NixO7–δ were investigated by using electrical resistivity and ac susceptibility measurements. X-ray powder diffraction has been used to find the lattice parameters of the samples. Electrical resistance and ac susceptibility measurements showed that the Tc values decrease from 91 K to 68 K, for the samples with y = 0, as the level of doping, x, increases from 0.0 to 0.25. As the Ca content increases, the Tc increases, from y = 0.05 (72 K) to y = 0.2 having Tc of 76 K. Analyzing the resistivity and ac susceptibility data, the following conclusions are drawn about the role of Ca and Ni doped simultaneously in the YBCO sample. (1) The conduction mechanism of electrons appears to follow a crossover from the purely metallic regime to the localization regime. The results are explained on the basis of hole localization and magnetic pair-breaking mechanism. (2) The co-substitution of calcium tends to counteract the some of the effect induced by Ni, but it cannot recover the decrease of the critical temperature.