纳米NiAl-Ni和Ni3Al-Ni合金的低温电阻特性

为了深入理解纳米Al-Ni合金低温下的电子输运过程，使用自主研发的电磁感应加热-自悬浮定向流法制备出Al，Ni和Al-Ni纳米合金粉末，并采用真空热压设备将纳米粉末压制成纳米晶块体，利用自主搭建的低温热电测量系统研究了Al-Ni纳米合金的电阻率随温度(8~300 K)的变化规律。研究结果表明:Al-Ni纳米合金由于形成有序晶相而仍然与Al，Ni纳米晶一样，电阻率随温度的降低而降低。纳米Ni₃Al-Ni和NiAl-Ni在居里温度点附近出现了电阻率随温度变化的极大值点，因为单质Ni的影响，Ni₃Al-Ni的居里温度比粗晶Ni₃Al提高了20 K。由于磁子-电子散射作用和声子-电子散射作用，纳米Ni₃Al-Ni，NiAl-Ni和Ni的电阻率在低温下(8~40 K)与温度呈T2和T4关系。

Resistivity of nanostructure NiAl-Ni and Ni3Al-Ni alloys at low temperature

Al, Ni and Al-Ni alloy powders were prepared by the flow-levitation method through electromagnetic induction heating, and the nano-powders were compressed into nanostructured samples by vacuum hot pressure sintering furnace. We used the four-point probe method to measure the values of electrical resistivity (ρ) of the nanostructured aluminum, nickel and Al-Ni alloy samples at temperature (T) ranging from 8 K to 300 K to explore the relationship between the electrical resistivity and temperature. The results show that the resistivity of nanostructured Al, Ni and Al-Ni alloys decreased with the decrease of temperature due to the formation of ordered crystalline phase. The nanostructured Ni₃Al-Ni and NiAl-Ni alloys showed a maximum value of resistivity to temperature slope near the Curie temperature, and the Curie temperature of Ni₃Al-Ni was 20 K higher than that of coarse-grained Ni₃Al because of the influence of nickel elemental. The resistivity of nanosturctured Ni₃Al-Ni, NiAl-Ni, and Ni show T2 and T4 law at low temperature (8-40 K) due to magneton-electron scattering and phonon-electron scattering.