Thermodynamic, Elastic, and Magnetic Properties of Solid Helium

Recent experimental studies of solid helium are reviewed with special attention given to specific heat, isochoric pressure, neutron scattering, sound velocity, and magnetic susceptibility measurements. The relationships among the properties are stressed. Low temperature properties of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, including exchange, nuclear spin ordering, the melting curve, and Pomeranchuk colling, are discussed. Phase separation in solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures is reviewed.