Orbital order and ferromagnetism in LaMn1-xGaO3

We study from first principles the magnetic, electronic, orbital and structural properties of the LaMnO3 doped with gallium replacing the Mn-site. The gallium doping reduces the Jahn-Teller effect, and consequently the bandgap. Surprisingly, the system does not go towards a metallic phase because of the Mn-bandwidth reduction. The Ga-doping tends to reduce the orbital order typical of bulk antiferromagnetic LaMnO3 and consequently weakens the antiferromagnetic phase. The Ga-doping favors the G-type orbital order and layered-ordered ferromagnetic perovskite at x=0.50, both effects contribute to the formation of the insulating ferromagnetic phase in LaMn1-xGaO3.

Automated summary

This study investigates the magnetic, electronic, orbital, and structural properties of Ga-doped LaMnO3. The gallium doping reduces the Jahn-Teller effect and the bandgap, but does not lead to a metallic phase due to the reduction in Mn bandwidth. Ga-doping also reduces the orbital order of the antiferromagnetic phase. At x=0.50, Ga-doping promotes the formation of an insulating ferromagnetic phase.