Nuclear Antiferromagnetism in SolidHe3

The nuclear magnetic susceptibility of pure solid ${\mathrm{He}}^3$ (1×${10}^{-5\mathrm{}}$ ${\mathrm{He}}^4$ impurity) at molar volumes of 23.3, 23.6, and 24.2 ${\mathrm{cm}}^3$/mole has been measured between 0.2 and 0.04°K. Antiferromagnetic nuclear ordering is indicated with the Néel temperature $T_{\mathrm{N}}$ increasing from (0.75±1)×${10}^{-3\mathrm{}}$°K at 23.3 ${\mathrm{cm}}^3$/mole to (2.4±1)×${10}^{-3\mathrm{}}$°K at 24.2 ${\mathrm{cm}}^3$/mole. Special attention has been given to thermal equilibrium.