The inverse spinels CoFe2O4 and NiFe2O4, which have been of particular interest over the past few years as building blocks of artificial multiferroic heterostructures and as possible spin-filter materials, are investigated by means of density functional theory calculations. We address the effect of epitaxial strain on the magneto-crystalline anisotropy and show that, in agreement with experimental observations, tensile strain favors perpendicular anisotropy, whereas compressive strain favors in-plane orientation of the magnetization. Our calculated magnetostriction constants λ100 of about -220 ppm for CoFe2O4 and -45 ppm for NiFe2O4 agree well with available experimental data. We analyze the effect of different cation arrangements used to represent the inverse spinel structure and show that both LSDA+U and GGA+U allow for a good quantitative description of these materials. Our results open the way for further computational investigations of spinel ferrites.
@article{arxiv.1006.5080,
title = {Epitaxial strain effects in the spinel ferrites CoFe2O4 and NiFe2O4 from first principles},
author = {Daniel Fritsch and Claude Ederer},
journal= {arXiv preprint arXiv:1006.5080},
year = {2015}
}