We present a comprehensive theory of the temperature- and disorder-dependence of half-metallic ferrimagnetism in the double perovskite Sr2FeMoO6 (SFMO) with Tc above room temperature. We show that the magnetization M(T) and conduction electron polarization P(T) are both proportional to the magnetization MS(T) of localized Fe spins. We derive and validate an effective spin Hamiltonian, amenable to large-scale three-dimensional simulations. We show how M(T) and Tc are affected by disorder, ubiquitous in these materials. We suggest a way to enhance Tc in SFMO without sacrificing polarization.
@article{arxiv.1107.0983,
title = {Theory of Half-metallic Ferrimagnetism in Double Perovskites},
author = {Onur Erten and O. Nganba Meetei and Anamitra Mukherjee and Mohit Randeria and Nandini Trivedi and Patrick Woodward},
journal= {arXiv preprint arXiv:1107.0983},
year = {2015}
}