Strain-tunable magnetic properties of epitaxial lithium ferrite thin film on MgAl2O4 substrates

Abstract

Epitaxial LiFe₅O₈ thin films with various thicknesses were fabricated on (001) MgAl₂O₄ substrates by using a high-pressure sputtering system. All the LiFe₅O₈ thin films have excellent epitaxial quality with ordered α-LiFe₅O₈ structure, and larger in-plane compressive and out-of-plane tensile strain can be obtained by decreasing the film thickness. Moreover, the in-plane compressive strain can significantly induce the enhancement of in-plane magnetization while the out-of-plane tensile strain tends to reduce the out-of-plane magnetization. It indicates that controlling the thickness of the films is an effective method to tailor the interface strain and further modify the magnetic properties of the epitaxial LiFe₅O₈ thin films.