Synthesis, crystal structure and magnetic properties of a new B-site ordered double perovskite Sr{sub 2}CuIrO{sub 6}

• Published in: Journal of solid state chemistry Vol. 220
• Main Authors: Vasala, Sami, Yamauchi, Hisao, Karppinen, Maarit
• Format: Journal Article
• Language: English
• Published: United States 15.12.2014
• Subjects: CATIONS; CRYSTAL STRUCTURE; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTERACTIONS; IODINE IONS; IRIDIUM; MAGNETIC PROPERTIES; OXIDES; OXYGEN; PEROVSKITE; SPIN GLASS STATE; STABILIZATION; SYNTHESIS
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/J.JSSC.2014.08.008

Here we synthesize and characterize a new double-perovskite oxide Sr{sub 2}CuIrO{sub 6}. The synthesis requires the use of high oxygen pressure to stabilize the VI oxidation state of iridium. The compound has a tetragonally-distorted crystal structure due to the Jahn–Teller active Cu{sup II} ion, and a high degree of B-site cation order. Magnetic transition is apparent at 15 K, but the zero-field-cooled and field-cooled susceptibilities diverge below this temperature. The high degree of cation order would exclude the possibility of a typical spin-glass, indicating that the divergence is probably due to a frustration of the magnetic interactions between Cu and Ir, with a high frustration factor of f≈25. - Graphical abstract: A new member of the A{sub 2}B′B″O{sub 6} double-perovskite family with JT-active Cu{sup II} at the B′ site and Ir{sup VI} at the B″ site is synthesized through high pressure synthesis and characterized for the structural and magnetic properties. - Highlights: • New member of the A{sub 2}CuB″O{sub 6} double-perovskite family is synthesized with B″=Ir. • Stabilization of Ir{sup VI} requires the use of high oxygen pressure synthesis. • Crystal structure is tetragonally distorted due to JT-active Cu{sup II}. • Divergence of ZFC and FC curves is seen below the T{sub N} of 15 K. • This is presumably due to a frustration effect.