Magnetic and electric properties of double-perovskites and estimation of their Curie temperatures by ab initio calculations

Abstract

First principles electronic structure calculations have been carried out on ordered double perovskites Sr_2B'B"O_6 (for B' = Cr or Fe and B" 4d and 5d transition metal elements) with increasing number of valence electrons at the B-sites, and on Ba_2MnReO_6 as well as Ba_2FeMoO_6. The Curie temperatures are estimated ab initio from the electronic structures obtained with the local spin-density functional approximation, full-potential generalized gradient approximation and/or the LDA+U method (U - Hubbard parameter). Frozen spin-spirals are used to model the excited states needed to evaluate the spherical approximation for the Curie temperatures. In cases, where the induced moments on the oxygen was found to be large, the determination of the Curie temperature is improved by additional exchange functions between the oxygen atoms and between oxygen and B' and B" atoms. A pronounced systematics can be found among the experimental and/or calculated Curie temperatures and the total valence electrons of the transition metal elements.

arXiv comment8 pages, 11 figures. Submitted to the Physical Review B

References in corpus (4)

• Electronic Structure of Sr_2FeMoO_6
• Strong ferromangnetism and weak antiferroamgnetism in double perovskites: Sr${}_2$Fe{/it M}O${}_6$ ({/it M}=Mo, W and Re)
• Pseudo-half-metalicity in the double perovskite Sr${}_2$CrReO${}_6$ from density-functional calculations
• Half Semimetallic Antiferromagnetism in the Sr${}_2$CrTO${}_6$ System, T=Os, Ru

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• Origin of Magnetism and trend in $T_c$ in Cr-based double perovskites: Interplay of two driving mechanisms
• High-temperature multiferroicity and strong magnetocrystalline anisotropy in 3d-5d double perovskites
• Effect of Chemical Pressure on High Temperature Ferrimagnetic Double Perovskites Sr2CrOsO6 and Ca2CrOsO6
• Electronic structure and magnetism in M(=IA, IIA)C compounds with the rocksalt structure
• Effect of Strontium substitution on the structural and magnetic properties of La1.8Sr0.2MMnO6 (M = Ni, Co) layered manganites
• Re-t2g-splitting-driven semiconductor gaps in ferrimagnetic double perovskite Ca2MReO6 (M=Cr,Fe) from first principles
• Understanding the Curious Magnetic State of Sr${}_3$OsO${}_6$
• Non-collinear Magnetic Order in the Double Perovskites: Double Exchange on a Geometrically Frustrated Lattice