Effect of nitrogen incorporation on the ordering transformation of CoPt in CoPt/TiN bilayer films
Effect of nitrogen incorporation on the ordering transformation of CoPt in CoPt/TiN bilayer films
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DOI：
10.1016/j.jmmm.2017.07.038
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发表时间：
2017-12
影响因子：
2.7
通讯作者：
Petrus Caesario;T. Harumoto;Yoshio Nakamura;Ji Shi
中科院分区：
文献类型：
--
作者：
Petrus Caesario;T. Harumoto;Yoshio Nakamura;Ji Shi
The effect of nitrogen incorporation on theL10ordering transformation of CoPt thin films deposited by dc magnetron sputtering on MgO substrate with/without TiN seed layers has been investigated. Without TiN seed layer, CoPt film is subjected to a tensile stress, and the perpendicular magnetic anisotropy (PMA) decreases with N2gas flow ratio. This is due to the degradation of tensile stress, which is proven to be beneficial to the ordering transformation ofL10CoPt. On the contrary, when sputtered on TiN seed layer, CoPt film is subjected to a compressive stress and the PMA increases with N2gas flow ratio. The increase of PMA is due to the increase in equilibrium vacancy concentration, which also promotes the diffusion of Co and Pt atoms during annealing. On quartz substrate, the maximum perpendicular coercivity of 11 kOe was obtained at the CoPt/TiN bilayer films with 50% partial N2gas flow ratio after post annealing at 700 °C. By partially flowing nitrogen during the deposition, a 200 °C reduction of ordering temperature was also obtained.
