纳米NiAl-Ni和Ni3Al-Ni合金的低温电阻特性

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

  • 摘要: 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T2T4关系。

     

    Abstract: 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.

     

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