Pressure and temperature dependence of the magnetic properties of nickel

The pressure dependence of the hyperfine field ($\nu$) of ${}_{}{}^{61}{}_{}{}^{}\mathrm{Ni}$ in pure nickel has been measured to 30 kbar at room temperature with the result ${\left(\frac{\partial \ln {\nu }_T}{\partial P}\right)}_T=(9.0\mathrm{}\pm 0.1)\times {10}^{-7\mathrm{}}$ ${\mathrm{kg}}^{-1\mathrm{}}$ ${\mathrm{cm}}^2$. The value at 0 K is calculated to be 8.1×${10}^{-7\mathrm{}}$ ${\mathrm{kg}}^{-1\mathrm{}}$ ${\mathrm{cm}}^2$. The temperature dependence of the hyperfine field of nickel at atmospheric pressure reported earlier has been corrected to constant volume, using the new value for ${\left(\frac{\partial \ln {\nu }_T}{\partial P}\right)}_T$, and is still found to be a measure of the magnetization. The large discrepancy between the temperature dependence of the magnetization predicted by spin-wave theory and that found by experiment is confirmed to be nearly proportional to $T^2$ as was reported previously.