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

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 alpha-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.