Understanding the Curious Magnetic State of Sr${}_3$OsO${}_6$

Abstract

Motivated by the recent report on high T${}_c$ ferromagnetic insulating state of single transition metal containing double perovskite compound, Sr${}_3$OsO${}_6$ (Wakabayashi et. al., Nature Commun {\bf 10} 535, 2019), we study this curious behavior by employing first-principles calculations in conjunction with exact diagonalization of full $t_{2g}$ multiplet problem of two Os sites. Our analysis highlights the fact that stabilization of Sr${}_3$OsO${}_6$ in the cubic phase in epitaxially grown thin film is the key to both ferromagnetic correlation and high temperature scale associated to it. This also provides a natural explanation for the sister compound, Ca${}_3$OsO${}_6$ to exhibit low T${}_N$ antiferromagnetism in its monoclinic structure. Further the insulating property is found to be driven by opening of Mott gap in the half filled spin-orbit coupled $j=3/2$ manifold of $d^2$ Os. We point out that Sr${}_2$CaOsO${}_6$ which naturally forms in the cubic phase would be worthwhile to explore as a future candidate to exhibit high T${}_c$ ferromagnetic insulating state in bulk form.

8 pages, 4 figures, to appear in Phys. Rev. B

References in corpus (5)

• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Electronic Structure, Phonons and Dielectric Anomaly in Ferromagnetic Insulating Double Perovskite La2NiMnO6
• Magnetic and electric properties of double-perovskites and estimation of their Curie temperatures by ab initio calculations
• Ba2NiOsO6: A Dirac-Mott insulator with ferromagnetism near 100 K
• Study of polycrystalline bulk Sr${}_3$OsO${}_6$ double-perovskite insulator: comparison with 1000 K ferromagnetic epitaxial films

Cited by in corpus (1)

• Sr4Os3O12- A Layered Osmate (V,VI) that is Magnetic close to Room Temperature