Temperature Dependence of the Hall Coefficients in Some Copper Nickel Alloys

Abstract

The two Hall coefficients and the resistivity of Cu-Ni alloys containing 80%, 70%, and 60% Ni have been measured from 4°K to 400°K. These alloys were chosen because early measurements had indicated that conduction in the $3d$ bands of these ferromagnetic alloys could be neglected. The values of ${R_0}^{*}$, from precise Hall measurements at high fields, are in excellent agreement with the predictions of the band model that divides the conduction band into parallel and antiparallel bands. The data on all three alloys fit the predicted curve at temperatures below their Curie Points and also fit the predicted Curie point anomaly due to $\frac{\partial M}{\partial B}\ne 0$ at high fields in this temperature region. The dependence of ${R_1}^{*}$ upon resistivity is in agreement with the law ${R_1}^{*}=A{\rho }^n$. For 80% and 70% Ni the coefficient $A$ and the exponent $n$ agree with the values obtained for pure Ni. A significant departure from the pure Ni value is observed, however, in the 60% Ni alloy. Evidence is presented that indicates this law should be extrapolated through the temperature region above the Curie point where the alloys are paramagnetic.