Ferromagnetic properties of Zn1−xMnxO epitaxial thin films

Abstract

We report on ferromagnetic characteristics of ${\mathrm{Zn}}_{\text{1−x}}{\mathrm{Mn}}_x\mathrm{O}$ $\text{(x=0.1}$ and 0.3) thin films grown on ${\mathrm{Al}}_2{\mathrm{O}}_3\text{(00⋅1)}$ substrates using laser molecular-beam epitaxy. By increasing the Mn content, the films exhibited increases in both the c-axis lattice constant and fundamental band gap energy. The Curie temperature obtained from temperature-dependent magnetization curves was 45 K for the film with $\text{x=0.3,}$ depending on the Mn composition in the films. The remanent magnetization and coercive field of ${\mathrm{Zn}}_{\text{0.9}}{\mathrm{Mn}}_{\text{0.1}}\mathrm{O}$ at 5 K were 0.9 emu/g and 300 Oe, respectively. For ${\mathrm{Zn}}_{\text{0.7}}{\mathrm{Mn}}_{\text{0.3}}\mathrm{O},$ the remanent magnetization at 5 K increased to 3.4 emu/g.