Oxygen Vacancy Effects in the Electronic and Magnetic Structure of  La0.7sr0.3mno3 Epitaxial Thin Films from First Principles

Abstract

La0.7Sr0.3MnO3 (LSMO) is a promising material for spintronic applications due to its robust ferromagnetism and complete spin polarization. However, these properties are known to degrade in thin films. Oxygen vacancies are believed to be a critical factor in this degradation, but experimentally isolating their effects has proven challenging. In this work, we use first-principles calculations to theoretically investigate how oxygen vacancies affect the magnetic structure of LSMO thin films. Our results reveal that oxygen vacancies act as scattering centers, leading to charge redistribution within the bulk layers. This redistribution disrupts the ferromagnetic double-exchange interaction and introduces competing super-exchange interactions, causing local spin flipping and ultimately reducing the overall magnetization.

Keywords: Manganites, Vacancies, Half-metals, Local DOS, DFT, Exchange Interactions