Electronic structure and magnetism of EuTiO3: A first-principles study

Abstract

Density-functional theory calculations were carried out for the multiferroic EuTiO3 using the LDA+U approach. Total-energy calculations for ferromagnetic (F), and antiferromagnetic A-, C-, and G-type arrangements in the cubic phase shows that the ground-state magnetic configuration is G-type antiferromagnetic for U≤6eV and ferromagnetic for U≥7eV. Values of first-and second-neighbour exchange integrals have been calculated by mapping the energy difference between the different magnetic configurations to a Heisenberg Hamiltonian. The system seems to be critically balanced between ferromagnetic and antiferromagnetic states for realistic values of U, and switches from antiferromagnetic to a ferromagnetic ground state on hydrostatic expansion of volume. © IOP Publishing Ltd.