Preparation condition, structure and superconductivity of LaBaMCu3Oy (M = Ba, Sr, Ca)

• Published in: Materials letters 1999-09, Vol.40 (5), p.222-227
• Main Authors: TAO, F, CHE, C. G, ZHOU, X. J, ZHAO, Z, ZHU, S. F, DONG, C, JIA, S. L, CHEN, H
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cuprates superconductors (high tc and insulating parent compounds); Exact sciences and technology; High-Tc compounds; Inorganic compounds; La-based cuprates; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Superconductivity; Water, oxides, hydroxides, peroxides
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/s0167-577x(99)00079-8

The effects of preparation conditions on the phase formation, structure and superconductivity for the LaBaMCu3Oy system were investigated to find the optimum preparation conditions of La123 type superconductors. In LaBa2Cu3Oy, La can substitute for Ba, but Ba cannot be substituted for La since the atmosphere of O2 or air is favourable for the substitution of La for Ba whereas the sintering and cooling atmospheres of N2 can suppress the substitution of La for Ba, which is a key procedure for obtaining high quality single phase La123 superconductors. The single phase LaBa2Cu3Oy superconductor with the highest Tc(0) of 97 K and Tc(onset) of 101 K has been obtained. With the same conditions, LaBaSrCu3Oy and LaBaCaCu3Oy superconductors with Tc(0) of 85.5 K and 80 K respectively were prepared. 23 refs.