Observation of Nuclear Magnetic Order in SolidHe3

Abstract

Measurements of $\frac{\mathrm{Tdp}}{\mathrm{dT}}$ have been made along the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ melting curve near an anomaly at $T_s=1.17\mathrm{}$ mK. It is found that the solid-${}_{}{}^3{}_{}{}^{}\mathrm{He}$ entropy decreases by 80% in an interval of 100 μK at $T_s$. This is attributed to onset of nuclear magnetic order.