Crystal Growth of a New 8H Perovskite Sr8Os6.3O24 Exhibiting High TC Ferromagnetism

TL;DR

This study reports the synthesis and characterization of a new hexagonal perovskite Sr8Os6.3O24 with high Curie temperature ferromagnetism, the highest among 5d oxide perovskites, revealing novel structural and magnetic properties.

Contribution

First synthesis of a hexagonal 5d oxide perovskite with high TC ferromagnetism and unique structural features.

Findings

Crystallizes in a hexagonal cell with specific lattice parameters

Exhibits spontaneous ferromagnetism below 430 K

Achieves the highest TC among 5d perovskite oxides

Abstract

Single crystals of a new twinned hexagonal perovskite compound Sr8Os6.3O24 have been synthesized, and structural and magnetic properties have been determined. The compound crystallizes in a hexagonal cell with lattice parameters a = 9.6988(3) {\AA} and c = 18.1657(5) {\AA}. The structure is an eight-layered hexagonal B-site deficient perovskite with the layer sequence (ccch)2 and represents the first example of a hexagonal structure among 5d oxides adopting a twin option. The sample shows spontaneous ferromagnetic magnetization below 430 K with a small saturation moment of 0.11 {\mu}B/Os ion. This is the highest Curie temperature (TC) reported for any bulk perovskite containing only 5d ions at the B site.