Anomalous low-temperature heat capacity in antiperovskite compounds

Guo Xin-Ge^{1, 2}, Lin Jian-Chao¹, Tong Peng^{1, †}, Lin Shuai¹, Yang Cheng¹, Lu Wen-Jian¹, Song Wen-Hai¹, Sun Yu-Ping^{1, 3, 4}

(color online) Specific heat plots of (C − γT)/T ³ versus T for antiperovskite compounds, ANMn₃ (A = Ag, Sn, Cu, Ga) (a), Ga_1−xMn_xNMn₃ (x = 0, 0.3), and Ag_1−xMn_xNMn₃ (x = 0, 0.4) (b), GaXMn₃, SnXMn₃, and AgXMn₃ (X = N, C) (c), and GaCM₃ and AlCM₃ (M = Fe, Co, Mn) (d).