New oxygen-deficient perovskite phase in the La1−xSrxCuO3−y system

✍ Scribed by Norimitsu Murayama; Yasuyoshi Torii

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 288 KB
• Volume: 109
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(89)90605-9

✦ Synopsis

In the Lal_xSrxCuO3_y system, a new nonstoichiometric perovskite solid solution was found to exist in a narrow range of O.200<~ x <~ 0.250. This perovskite phase has a tetragonal distortion based on a Jahn-Teller effect of the copper ion. The lattice parameters are closely related to those of the simple cubic perovskite: a = 10.8492( 6) and c = 3.8628(4) ~ for x = 0.200, and a = 10.8296( 8) and c = 3.8623(5) ft for x = 0.250, where a = 2(2 I/2)c. These perovskite compounds exhibited metallic conductivity and no superconducting transition was observed above 10 K. With increasing Sr content, the crystal lattices contracted and the resistivity ratio of p(T) to P2~o decreased. When annealed at 8800C in a flowing N 2 gas, Lao.75Sro.25Cu02.52 decomposed to superconducting Lae_xSrxCuO 4, La2SrCu206 and unknown phases.