Magnetic structure of the quasi-one-dimensionalLa3OsO7as determined by neutron powder diffraction

Abstract

Insulating 5d3 La 3 OsO 7 and the isostructural hole-doped analog La 2.

Magnetic and electronic properties of La3 MO7 and possible polaron formation in hole-doped La3 MO7 (M = Ru and Os)

“…The Ca-doped La 3 OsO 7 was also studied. Despite the change of nominal carrier density, surprisingly, this hope-doped system remain an insulator (or a semiconductor), violating the rigid band scenario [16]. Similar robust insulating behavior was also found in some doped iridates [17,18], which was expected to show superconductivity after doping [19,10].…”

“…It is found that U eff (Ru)=1 eV is the best choice to reproduce the experimental structure of La 3 RuO 7 , while for La 3 OsO 7 the bare GGA without U eff is the best choice. Comparing with experimental values [16,20], the deviation of calculated lattice constants are only < 0.8% for La 3 OsO 7 , and 0.5% for La 3 RuO 7 , providing a good start point to study other physical properties. These choices of U eff are quite reasonable considering the gradually deceasing Hubbard repulsion from 3d to 5d.…”

“…As revealed in PDOS, there exists strong hybridization between Os's 5d and O's 2p orbitals around the Fermi energy level, owning to the spatial extended 5d orbitals. In fact, the previous neutron study also attributed the reduced moment to the hybridization between Os and O [16].…”

“…63 Cmcm) structures [16,24], the lattice constants and inner atomic positions are fully optimized till the Hellman-Feynman forces are all less than 0.01 eV/Å. The Hubbard repulsion U eff (= U − J) is imposed on Ru's 4d orbitals and Os's 5d orbitals [25].…”

“…Taking La 3 OsO 7 for example, recent experimental studies reported its structural, transport, and magnetic properties, characterized by magnetic susceptibility, x-ray diffraction, as well as neutron diffraction [16]. The corner-shared OsO 6 octahedra form chains along the [001] direction of the orthorhombic framework.…”