Crystal Structure and Magnetic Properties of B-Site Ordered Perovskite-type Oxides A2CuB′O6 (A=Ba, Sr; B′=W, Te)

✍ Scribed by Daisuke Iwanaga; Yoshiyuki Inaguma; Mitsuru Itoh

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 163 KB
• Volume: 147
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8273

✦ Synopsis

Four cuprate perovskites with the general formula A 2 CuBO 6 (A ‫؍‬ Ba, Sr; B ‫؍‬ W, Te) were synthesized and the structural and the magnetic properties were investigated. Among four samples, perovskite Ba 2 CuTeO 6 was formed only under high pressure. All the samples were tetragonally distorted B-site ordered perovskite-type oxides with I4/m symmetry. The CuO octahedra is elongated by the Jahn+Teller e4ect of Cu 2؉ ion and CuO 6 and WO 6 (or TeO 6 ) octahedra rotates about the [001] direction. These compounds show two-dimensional antiferromagnetic behavior, because of the superexchange interaction between Cu 2؉ ions via an array of nonmagnetic ions, O+W+O (or O+Te+O) in the ab-plane perpendicular to the c-axis. The detailed analysis of the crystal structure made clear that the strength of the superexchange interaction depends more on the bond angle Cu+O+W (or Cu+O+Te) than the distance between Cu 2# ions in the abplane.