Magnetic properties of La0.67Sr0.33MnO3/BiFeO3(001) heterojunctions: Chemically abrupt vs. atomic intermixed interface

Using first-principles density-functional calculations, we address the magnetic properties of the ferromagnet/antiferromagnet La0.67Sr0.33MnO3/BiFeO3(001) heterojunctions, and investigate possible driving mechanisms for a ferromagnetic (FM) interfacial ordering of the Fe spins recently observed experimentally. We find that the chemically abrupt defect-free La0.67Sr0.33MnO3/BiFeO3(001) heterojunction displays, as ground state, an ordering with compensated Fe spins. Cation Fe/Mn intermixing at the interface tends to favour, instead, a FM interfacial order of the Fe spins, coupled antiferromagnetically to the bulk La0.67Sr0.33MnO3 spins, as observed experimentally. Such trends are understood based on a model description of the energetics of the exchange interactions. Copyright (c) EPLA, 2012