On the phase transition(s) of magnetite at low temperatures

Abstract

Specific heat measurements have been performed on stoichiometric magnetite in order to study the occurrence of a multiple phase transition near the Verwey temperature and the possibility of an additionl phase transition near 10 K. It was found that besides the Verwey transition at 123 K, which is an ordering of the Fe²⁺ and Fe³⁺ ions, an intrinsic anomaly occurs in the specific heat at about 110 K, as well as in the magnetization, which can be attributed to a spin rotation of the Fe²⁺ ion. No evidence was found for a phase transition near 10 K.