Effects of electron correlations application to Ti atoms on physical properties of (LaMnO₃)_m/(SrTiO₃)_n superlattices

Magnetic structures and Curie temperatures of the (LaMnO₃)_m/(SrTiO₃)_n superlattices (SLm–n) with m=1, 2, 3 and n=1, 2, 3, 8 were investigated, using density functional theory implemented in Quantum-Espresso open source code. By applying on-site coulomb interaction (Hubbard term U) to Ti atoms for all of these superlattices, using Stoner–Wolfarth model, it was found that the magnetic order of interfacial atoms of these superlattices changed to ferromagnetic by implying U=5 eV on Ti atoms. The inclusion of electron–electron correlation with U=5 eV on the Ti atoms for all of the superlattices made the two dimensional electron gas (2DEG) formed at the interfaces, half-metallic. The obtained values of Curie temperature, calculated within mean field approximation with U=5 eV on the Ti atoms, are in good agreement with the experimental results. - Highlights: • Calculated the magnetic structure and Curie temperature of the (LaMnO₃)_m/(SrTiO₃)_n superlattices with m=1, 2, 3 and n=1, 2, 3, 8 by mean field approximation. • By implying U=5 eV on the Ti atoms, the magnetic order of interfacial atoms of these superlattices has changed to ferromagnetic. • The 2DEG formed at the interface half-metallic have made in these superlattices by the inclusion of electron-electron correlation with U=5 eV on the Ti atoms for all of the superlattices.