The Electrical Resistivity and Thermopower of Nickel-Copper Alloys

Measurements are presented of the electrical resistivity, ρ, and thermoelectric power, S, of a number of Ni-Cu alloys in the mid-range of composition at temperatures between 200 K and 900 K. For alloys containing between 45 % and 60 % Cu, ρ falls with T between ~ 200 K and ~ 690 K in reasonable agreement with earlier work. For these same specimens hysteresis effects ~ 1 % appear in ρ below 690 K every time the specimen is cycled above that temperature. By contrast, there are no anomalies in the S versus T curves of these alloys at any temperature. Rough values are given for the critical exponents of the decrease in dρ/dT above the Curie points.