Charge transfer, confinement, and ferromagnetism in LaMnO3/LaNiO3 (001) superlattices

Using first-principles density functional theory calculations, we investigated the electronic structure and magnetic properties of (LaMnO3)(m)/(LaNiO3)(n) superlattices stacked along the (001) direction. The electrons are transferred from Mn to Ni, and the magnetic moments are induced at Ni sites that are paramagnetic in bulk and other types of superlattices. The size of the induced moment is linearly proportional to the amount of transferred electrons, but it is larger than the net charge transfer. The charge transfer and magnetic properties of the (m,n) superlattice can be controlled by changing the m/n ratio. Considering the ferromagnetic couplings between Mn and Ni spins and the charge-transfer characteristic, we propose the (2,1) superlattice as the largest moment superlattice. carrying similar to 8 mu(B) per formula unit.