Influence of Polarization, Strain, and Doping on the Magnetoelectric Properties of LSMO/PZT Interfaces: An Ab Initio Study

We apply ab initio methods based on density functional theory to study the influence of polarization, strain, and doping on the magnetoelectric coupling at the (0,0,1) interface between PZT (PbZr0.2Ti0.8O3) and LSMO at three different doping levels (La0.8Sr0.2MnO3, La0.67Sr0.33MnO3, and La0.5Sr0.5MnO3). The effects of strain are modeled by applying a ±1% uniaxial strain in the direction orthogonal to the LSMO/PZT interface. Our calculations show that the magnetic properties of the LSMO layer are strongly influenced by the direction of PZT polarization, doping concentration, and the applied uniaxial strain. An increase of the Sr doping level increases the energy of the ferromagnetic phase and decreases the energy of the antiferromagnetic phase of LSMO. A positive strain stabilizes the ferromagnetic configuration of LSMO, whereas a negative strain stabilizes the antiferromagnetic configuration of LSMO. The results of our study are consistent with the available experimental data.