Resistivity of nanostructure NiAl-Ni and Ni₃ Al-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 nanostructured 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. (authors)