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通过磁控溅射制备了AlNi纳米合金薄膜,并利用自制的直排四探针低温测量系统测量了薄膜电阻率随温度(8~300K)的变化规律。结果表明:由于电子-声子和电子-磁子相互作用,纯Al和Ni纳米晶薄膜的电阻率分别呈现出正的电阻率温度系数,且电子-磁子散射对电阻率的贡献主要体现在高温区(80~300K),在低温区(<40K)电子-晶界/表面散射对电阻率的贡献占主导地位。Ni原子掺入量的增加,诱导了纳米晶薄膜无序程度的增强,从而使Al1-xNix纳米合金薄膜逐渐由晶体的金属特性过渡到半导体特性,导致其呈现出负的电阻率温度系数。由于增强的电子极化效应,Al1-xNix纳米合金薄膜电阻率与温度的关系并不完全遵循半导体的热激发导电模型。
AlNi nano-alloy thin films were prepared by magnetron sputtering. The variation of the resistivity of the films with temperature (8 ~ 300K) was measured by a self-made low-temperature measurement system with a straight four-probe. The results show that the resistivities of pure Al and Ni nanocrystalline films exhibit positive temperature coefficient of resistivity respectively due to the interaction of electron-phonon and electron-magneton, and the contribution of electron-magneton scattering to resistivity is mainly reflected in The contribution of the electron-grain boundary / surface scattering to the resistivity is dominant in the high temperature range (80-300 K) at low temperature (<40 K). The increase of Ni atomic doping induces the enhancement of disorder degree of nanocrystalline thin films, which makes the Al1-xNix nanocrystalline thin films gradually transition from the crystalline to semiconducting properties, resulting in negative temperature coefficient of resistivity. Due to the enhanced electron polarization, the resistivity of Al1-xNix nanostructured thin film does not completely follow the thermal conductivity of the semiconductor.