We propose a model for the multiorbital material Sr2CrOsO 6, an insulator with remarkable magnetic properties and the highest Tc 725 K among all perovskites with a net moment. We derive a new criterion for the Mott transition (U1U2) 1/2>2.5W by using slave-rotor mean field theory, where W is the bandwidth and U1(2) are the effective Coulomb interactions on Cr(Os) including Hund's coupling. We show that Sr2CrOsO6 is a Mott insulator, where the large Cr U1 compensates for the small Os U2. The spin sector is described by a frustrated antiferromagnetic Heisenberg model that naturally explains the net moment arising from canting and also the observed nonmonotonic magnetization M(T). We predict characteristic magnetic structure factor peaks that can be probed by neutron experiments.
ASJC Scopus subject areas
- Physics and Astronomy(all)