Specific Heat of a Magnetite Crystal at Liquid Helium Temperatures

Abstract

The heat capacity of a large natural crystal of magnetite was measured between 1.8 and 4.2\ifmmode^\circ\else\textdegree\fi{}K. The specific heat, as a function of temperature, is resolved into two parts: a ${T}^{3}$ term that presumably is the lattice heat, and a ${T}^{\frac{3}{2}}$ term that may be identified as a spin-wave contribution to the specific heat.