Structure and magnetic properties for L1 0-ordered FeNi films prepared by alternate monatomic layer deposition

Abstract

Alternate monatomic layer (ML) deposition technique has been used to fabricate a metastable L1 0-ordered phase of FeNi alloys. The films were prepared by alternating Fe (0 0 1) and Ni (0 0 1) MLs on MgO (0 0 1) substrates at various temperatures T S in the range between 80 and 400 °C. It has been found that the degree of long-range order S evaluated by X-ray diffraction increases with T S, and it has a maximum at T S=240 °C. With further increase of T S, S shows a drastic decrease, and almost disappears at T S=280 °C. 280 °C is close to the order–disorder transformation temperature in the thermal equilibrium. The variation of K u shows the same tendency as that of S, suggesting the formation of L1 0-ordered FeNi alloy in the range of T S=200–260 °C. Maximum values of S=0.6±0.2 and K u=6.3×10 6 (erg/cm 3) are obtained at T S=240 °C.