Ferromagnetism above 1000 K in a highly cation-ordered double-perovskite insulator Sr3OsO6

• Published in: Nature communications Vol. 10; no. 1; pp. 535 - 8
• Main Authors: Wakabayashi, Yuki K., Krockenberger, Yoshiharu, Tsujimoto, Naoto, Boykin, Tommy, Tsuneyuki, Shinji, Taniyasu, Yoshitaka, Yamamoto, Hideki
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.02.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 147/137; 639/301/119/2793; 639/301/119/997; Curie temperature; Electronic structure; Electrons; Epitaxial growth; Fabrication; Ferromagnetism; Humanities and Social Sciences; Insulators; multidisciplinary; Oxides; Permanent magnets; Perovskites; Scanning electron microscopy; Scanning transmission electron microscopy; Science; Science (multidisciplinary); Spin-orbit interactions; Strontium titanates; Substrates; Temperature effects; Transmission electron microscopy
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-08440-6

Magnetic insulators have wide-ranging applications, including microwave devices, permanent magnets and future spintronic devices. However, the record Curie temperature ( T C ), which determines the temperature range in which any ferri/ferromagnetic system remains stable, has stood still for over eight decades. Here we report that a highly B-site ordered cubic double-perovskite insulator, Sr 3 OsO 6 , has the highest T C (of ~ 1060 K) among all insulators and oxides; also, this is the highest magnetic ordering temperature in any compound without 3 d transition elements. The cubic B-site ordering is confirmed by atomic-resolution scanning transmission electron microscopy. The electronic structure calculations elucidate a ferromagnetic insulating state with J eff  = 3/2 driven by the large spin-orbit coupling of Os 6+ 5 d 2 orbitals. Moreover, the Sr 3 OsO 6 films are epitaxially grown on SrTiO 3 substrates, suggesting that they are compatible with device fabrication processes and thus promising for spintronic applications. Pursuing high Curie temperature magnetic insulators has been one of the extensively studied subjects due to their wide appeal for spintronic applications. Here the authors experimentally and theoretically demonstrate a record high Curie temperature over 1000 K in B-site ordered double-perovskite, Sr3OsO6.