Field-Independent Features in the Magnetization and Specific Heat of Sm3Co4Ge13

The cubic intermetallic compound Sm3Co4Ge13 (space group Pm (3) over barn) possesses a cage-like structure composed of Ge and displays an antiferromagnetic transition at T-N approximate to 6 K in magnetization, M (T), specific heat, C-p (T) and in thermal conductivity, kappa(T). The magnetic transition at T-N is observed to be robust against applied magnetic fields up to 9 T. From the analysis of specific heat, a Sommerfeld coefficient gamma = 80(2) mJ/mol-Sm K-2 is estimated. The magnetic entropy released at T-N is estimated as lower than that of a doublet, R ln(2). A positive Seebeck coefficient is observed for the thermopower, S (T). Photoemission spectroscopy reveals distinct electronic character of the near-E-F valence band states arising out of Co(3d)-Sm(4 f) hybridization and Sm(4 f) electron correlation. The unusual field-independent features in magnetization, specific heat and electrical transport is an indication of the significant correlation between f and d wave functions.