Effective three-band model for double perovskites

Abstract

We start from a six-band model describing the transition-metal t2g orbitals of half-metallic double perovskite systems, such as Sr2FeMoO6, in which only one of the transition metal ions (Fe) contains important intratomic repulsion Ufe. By eliminating the Mo orbitals using a low-energy reduction similar to that used in the cuprates, we construct a Hamiltonian which contains only effective t2g Fe orbitals. This allows to treat exactly Ufe, and most of the Fe-Mo hopping. As an application, we treat the effective Hamiltonian in the slave-boson mean-field approximation and calculate the position of the metal-insulator transition and other quantities as a function of pressure or on-site energy difference.

8 pages, 3 figures

References in corpus (3)

• Strong ferromangnetism and weak antiferroamgnetism in double perovskites: Sr${}_2$Fe{/it M}O${}_6$ ({/it M}=Mo, W and Re)
• Ab-initio study of disorder effects on the electronic and magnetic structures of Sr${}_2$FeMoO${}_6$
• Metal-insulator transition in the double perovskites

Cited by in corpus (7)

• Theory of Half-Metallic Double Perovskites I: Double Exchange Mechanism
• Phase diagram and influence of defects in the double perovskites
• Theory of Half-Metallic Double Perovskites II: Effective Spin Hamiltonian and Disorder Effects
• Polarization dependence of x-ray absorption spectra in Na_xCoO_2
• Effective Hamiltonian for transition-metal compounds. Application to Na_xCoO_2
• Electronic structure and Fermi surface tolopogy of Na${}_x$CoO${}_2$
• Magnetic and orbital ordering of RuO2 planes in RuSr2(Eu,Gd)Cu2O8