Ferrimagnetism induced by thermal vibrations in oxygen-deficient manganite heterostructures

Abstract

Superexchange most often leads to antiferromagnetism in transition-metal perovskite oxides, yet ferromagnetism or ferrimagnetism would be preferred for many applications, for example in data storage.While alloying, epitaxial strain, and defects were shown to lead to ferromagnetism, engineering this magnetic order remains a challenge. We propose, based on density functional theory calculations, a novel route to defect-engineer ferrimagnetism, which is based on preferential displacements of oxygen vacancies due to finite temperature vibrations. This mechanism has an unusual temperature dependence, as it is absent at 0 K, strengthens with increasing temperature, before vanishing with increasing thermal disorder, giving it a unique experimentally detectable signature.