Canted ferrimagnetism and giant coercivity in the non-stoichiometric double perovskite La2Ni1.19Os0.81O6
arXiv:1802.03874 · doi:10.1103/PhysRevB.97.184407
Abstract
The non-stoichiometric double perovskite oxide La2Ni1.19Os0.81O6 was synthesized by solid state reaction and its crystal and magnetic structures were investigated by powder x-ray and neutron diffraction. La2Ni1.19Os0.81O6 crystallizes in the monoclinic double perovskite structure (general formula A2BB'O6) with space group P21/n, where the B site is fully occupied by Ni and the B' site by 19 % Ni and 81 % Os atoms. Using x-ray absorption spectroscopy an Os4.5+ oxidation state was established, suggesting presence of about 50 % paramagnetic Os5+ (5d3, S = 3/2) and 50 % non-magnetic Os4+ (5d4, Jeff = 0) ions at the B' sites. Magnetization and neutron diffraction measurements on La2Ni1.19Os0.81O6 provide evidence for a ferrimagnetic transition at 125 K. The analysis of the neutron data suggests a canted ferrimagnetic spin structure with collinear Ni2+ spin chains extending along the c axis but a non-collinear spin alignment within the ab plane. The magnetization curve of La2Ni1.19Os0.81O6 features a hysteresis with a very high coercive field, HC = 41 kOe, at T = 5 K, which is explained in terms of large magnetocrystalline anisotropy due to the presence of Os ions together with atomic disorder. Our results are encouraging to search for rare earth free hard magnets in the class of double perovskite oxides.
arXiv commentsubmitted to PRB
References in corpus (14)
- Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
- Multifunctional L10-Mn1.5Ga films with ultrahigh coercivity, giant perpendicular magnetocrystalline anisotropy and large magnetic energy product
- Novel magnetism of Ir5+ ions in the double perovskite Sr2YIrO6
- Ba2YIrO6: A cubic double perovskite material with Ir5+ ions
- The frustrated FCC antiferromagnet Ba2YOsO6: structural characterization, magnetic properties and neutron scattering studies
- Ba2NiOsO6: A Dirac-Mott insulator with ferromagnetism near 100 K
- New Evidence for a Low-Temperature Magnetic Ground State in Double-Perovskite Iridates with Ir5+(5d4) Ions
- The iridium double perovskite Sr2YIrO6 revisited: A combined structural and specific heat study
- Understanding the Magnetic Puzzles of Double Perovskites A2FeOsO6 (A=Ca, Sr)
- Magnetism out of disorder in a J=0 compound Ba2YIrO6
- Influence of structural distortions on the Ir magnetism in Ba2-xSrxYIrO6 double perovskites
- The role of nonmagnetic d0 vs. d10 B-type cations on the magnetic exchange interactions in osmium double perovskites
- Fragile singlet ground state magnetism in pyrochlore osmates R2Os2O7 (R=Y and Ho)
- Magnetic Structure of the Quasi-One-Dimensional La3OsO7 as Determined by Neutron Powder Diffraction