Field Dependence of Magnetic Phase Transition in Metallic Ferromagnet CoS₂ --- Specific Heat Measurements ---

Abstract

We performed specific heat measurements of CoS₂ in a magnetic field of 0 T ≤ H ≤ 5 T over a broad temperature range (30 K < T < 250 K)by means of ac-calorimetory.The magnetic phase transition was significantly rounded toward the high-temperature sidewithout considerable change in the total magnetic entropy, while the field variation obeyed the Maxwell relation.We also found a magnetic equation of state for C_H(T), which includes critical indices α, β and δ determined from the previous zero-field measurements.