Nature of low-temperature phase transitions in CaMn7O12

作者：Volkova O^*; Arango Y; Tristan N; Kataev V; Gudilin E; Meier D; Lorenz T; Buchner B; Vasil'ev A

来源：JETP Letters, 2005, 82(7): 444-446.

DOI：10.1134/1.2142874

New data on the specific heat, thermal expansion, and magnetization of the CaMn7O12 phase require a revision of the current concepts of the sequence of phase transitions in this compound. It is found that a spin-glass phase transition occurs in CaMn7O12 at T-M = 49 K, whereas the transition at T-S = 89 K exhibits the features of a first-order phase transition and thereby is apparently of structural origin. In the range T-M < T < T-S, the CaMn7O12 compound exhibits negative thermal expansion, which is also indicative of structural changes.

• 出版日期2005