Formation and magnetic properties of metastable phases observed in the Fe_(50)(Hf_xTa_(1-x))_(50) films by ion beam mixing

摘要

Metastable phase formation and magnetic properties of the Fe_(50)(Hf_xTa_(1-x))_(50) (x-0, 0.2.....and 1) thin films induced by ion beam mixing are studied. The results show that unique amorphous phases could be formed in all the six multilayered films. Interestingly, preferred orientations and formation of BCC-Hf phase were observed in the Fe_(50)Hf_(50) multilayered films at as-deposited state and after irradiated to doses less than 6 × 10~(14) Xe~+/cm~2. In addition, good soft magnetic properties were obtained in the formed amorphous phases. The Fe_(50)Hf_(40)Ta_(10) amorphous phase owns the maximum magnetization of 45 emu/g (i.e., 1.21 μB per Fe atom) at 5 K, with a saturate magnetization of 7.5 emu/g and a small coercivity Hc = 7 Oe at room temperature. The possible mechanisms responsible for the observations are discussed in terms of atomic collision theory and crystallography.