Ferrimagnetism in the double perovskite Ca2FeOsO6: a density functional study

Abstract

Using density functional calculations, we find that the newly synthesized Ca${}_2$FeOsO${}_6$ has the high-spin Fe${}^{3+}$ ($3d^5$)-Os${}^{5+}$ ($5d^3$) state. The octahedral Os${}^{5+}$ ion has a large intrinsic exchange splitting, and its $t_{2g\uparrow }^3$ configuration makes the spin-orbit coupling ineffective. Moreover, there is a strong antiferromagnetic (AF) coupling between the neighboring Fe${}^{3+}$ ($S$ = 5/2) and Os${}^{5+}$ ($S$ = -3/2), but the AF couplings within both the fcc Fe${}^{3+}$ and Os${}^{5+}$ sublattices are one order of magnitude weaker. Therefore, a magnetic frustration is suppressed and a stable ferrimagnetic (FiM) ground state appears. This FiM order is due to the virtual hopping of the $t_{2g}$ electrons from Os${}^{5+}$ ($t_{2g\downarrow }^3$) to Fe${}^{3+}$ ($t_{2g\uparrow }^3{e}_{g\uparrow }^2$). However, if the experimental bended Fe${}^{3+}$-O${}^{2-}$-Os${}^{5+}$ exchange path gets straight, the $e_g$ hopping from Fe${}^{3+}$ ($t_{2g\uparrow }^3{e}_{g\uparrow }^2$) to Os${}^{5+}$ ($t_{2g\uparrow }^3$) would be facilitated and then a ferromagnetic (FM) coupling would occur.

arXiv comment5 pages, 5 figures

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Cited by in corpus (13)

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• Giant magnetic anisotropy of Co, Ru, and Os adatoms on MgO (001) surface
• Ba2NiOsO6: A Dirac-Mott insulator with ferromagnetism near 100 K
• Super-Exchange Theory for Polyvalent Anion Magnets
• Long-range magnetic interaction and frustration in double perovskite Sr${}_2$NiIrO${}_6$
• Understanding the Magnetic Puzzles of Double Perovskites A2FeOsO6 (A=Ca, Sr)
• The role of nonmagnetic d0 vs. d10 B-type cations on the magnetic exchange interactions in osmium double perovskites
• Room-temperature ferrimagnetism of anti-site-disordered Ca2MnOsO6
• Half Metal Transition Driven by Doping Effects in Osmium Double Perovskite
• New Buckled Honeycomb Lattice Compound Sr3CaOs2O9 Exhibiting Antiferromagnetism above Room Temperature
• Re-t2g-splitting-driven semiconductor gaps in ferrimagnetic double perovskite Ca2MReO6 (M=Cr,Fe) from first principles
• Magnetic frustration in the cubic double perovskite Ba2NiIrO6
• Spin-Orbital States and Strong Antiferromagnetism of Layered Eu${}_2$SrFe${}_2$O${}_6$ and Sr${}_3$Fe${}_2$O${}_4$Cl${}_2$