High pressure high temperature (HPHT) synthesis and magnetism of Cr-12s2 copper oxides with fluorite-structured layers between CuO2 planes

✍ Scribed by V.P.S. Awana; A. Ubaldini; S. Balamurugan; H. Kishan; E. Takayama-Muromachi

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 169 KB
• Volume: 460-462
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.03.037

✦ Synopsis

The three first members of the Cr-12s2 (s = 1, 2, 3) homologous series, i.e. CrSr 2 YCu 2 O 8 (Cr-1212), CrSr 2 (Y 1.5 Ce 0.5 )Cu 2 O 10 (Cr-1222) and CrSr 2 (Y 1 Ce 2 )Cu 2 O 12 (Cr-1232) are synthesized by high pressure high temperature (HPHT) 6 GPa and 1550 °C process. Though the Cr-1212 and Cr-1232 could not be formed in single phase with full Cr, the Cr-1222 is achieved in pure phase with space group I4/mmm. These compounds belong to the multi-layered copper oxides series that differ from each other only in terms of the (Ce,Y)-[O 2 -(Ce,Y)] sÀ1 layer blocks between two identical CuO 2 planes with s = 1, 2 and 3. At 5 K, the magnetization M(H) experiments showed some ferromagnetic like hysteresis loops though the characteristic M r and H c were not seen clearly. None of the studied compounds exhibited superconductivity down to 5 K.