System*

We present results of heat capacity (HC) measurements on filled skutterudite Pr_1-xEu_xPt₄Ge₁₂ (0 ≤ x ≤ 1) system to investigate the effect of Eu substitution on superconductivity (SC) and magnetism in this system. Increasing Eu content leads to the suppression of the SC transition temperature (T_c), with no evidence of SC for samples with x > 0.5 both from resistivity and HC measurements down to 0.5 K. The x > 0.7 samples display antifferomagnetism (AFM) with the Neel temperature increasing with increasing Eu content. The HC data reveal the presence of HC anomaly for the whole Eu doping range (0.05 ≤ x ≤ 1). The HC peak for the samples with x > 0.5 reflects the AFM of Eu moments since it is suppressed to lower T with increasing magnetic field. The HC peak for the samples with x ≤ 0.5 is a result of a net moment present at T < T_c since the position of the peak shifts to higher T with increasing magnetic field. In addition, the magnetic entropy increases linearly with increasing Eu content and it reveals an octet ground state, i.e., S = xRln8. The net internal field lifts this degeneracy and gives rise to the Schottky anomaly in HC.