L10-ordered MnAl thin films with high perpendicular magnetic anisotropy

Abstract

L10-ordered MnAl thin films were epitaxially grown by sputtering. The film composition dependences of structural and magnetic properties were systematically investigated in the MnAl thin films. Both the L10-ordered parameter and the perpendicular magnetic anisotropy energy strongly depended on the composition of the MnAl thin films. The MnAl thin films with a Mn composition of 53-54 at.% showed both the highest L10-ordered parameter and the perpendicular magnetic anisotropy. The substrate and annealing temperatures were optimized to improve the magnetic properties and surface morphology. We have fabricated MnAl thin films with both a very high Ku of 12 ' 106 erg/cm3 and a small surface roughness of ca. 0.2nm by optimizing the film composition and substrate and annealing temperatures. These results are useful guidelines for the fabrication of highly L10-ordered MnAl thin films with a large perpendicular magnetic anisotropy.