The effect of Fe doping on the crystallization kinetics of Ni-Mn-Sn free-standing alloy thin films

The exploration of Fe doping on crystallization behavior of Ni-Mn-Sn alloy thin films is crucial for its application, but remains unknown. Here, we investigated the effect of Fe doping on the crystallization kinetics of Ni-Mn-Sn free-standing alloy thin films by differential scanning calorimetry (DSC) in the mode of non-isothermal and isothermal conditions. In the case of non-isothermal crystallization, it is found that the crystallization peak temperatures of Ni50−xMn39Sn11Fex (x = 0, 0.5, 2, 4) free-standing alloy thin films increase with increasing Fe content. The apparent activation energy from the amorphous state to crystallization which determined by Kissinger's method increase with increasing Fe content. The local activation energy is determined by Doyle method. In the case of isothermal crystallization, the crystallization kinetics was modeled by the Johnson-Mehl-Avrami equation. The Avrami exponents were calculated to be in the range of 1 to 1.5. The local Avrami exponents indicating that the crystallization mechanism of Ni50−xMn39Sn11Fex (x = 0, 0.5, 2, 4) free-standing thin films is all from diffusion-controlled one-dimensional growth to diffusion-controlled two-dimensional and three-dimensional growth.