Low-temperature heat capacities and Verwey transition of magnetite

Abstract Heat capacities of stoichiometric magnetite crystals (Fe 3 O 4 ) were measured by adiabatic calorimetry from T = 13 K to 300 K. The Verwey transition was observed as a single sharp anomaly at T = 123.82 K in the heat-capacity curve. The transition molar enthalpy Δ trs H m and entropy Δ trs S m including the tail portion extending from about T = 80 K to 230 K were estimated as 980.8 J·mol -1 and 7.67 J·K -1 ·mol -1 , respectively. The thermodynamic properties of the transition are discussed. Several thermodynamic functions were calculated from the measured heat capacities and tabulated at round temperatures.