First-principle investigation on perovskite La_1-xEu_xGaO₃

The pseudopotential method has been used to investigate the structural, electronic and magnetic properties of La_1-xEu_xGaO₃ (x=0, 0.25, 0.5, 0.75, and 1) within the scheme of generalized gradient approximation. The spin-polarized calculations demonstrate that the ground state is an antiferromagnetic insulator for x≤0.5, while it is ferromagnetic half-metal at x>0.5. The substitutions of magnetic Eu ions for non-magnetic La ions produce and strength spin polarization, which forcefully urges the system from the insulator to the half metal. Meanwhile, Eu doping strengthens a stoner mechanism for ferromagnetism of La_1-xEu_xGaO₃ (x=0.75 and 1), which may lead to a rapid increasing in the total magnetic moment and therefore, antiferromagnetic-ferromagnetic transition happens.