Low-temperature specific heat of (Co₇₈Fe₂₂)₃V

Using a small-sample calorimeter, the specific heat of (Co₇₈Fe₂₂)₃V alloy has been measured in the temperature range 2-12 K in both the longrange ordered and disordered states. Contrary to the usual behavior in paramagnetic metals and alloys, the temperature dependence of the specific heat C_p(T) measured can be represented as C_p(T) = A + BT in the temperature range investigated. The anomalies in C_p(T) are discussed. It is found that although the theory of Hahn and Wohlfarth could, in principle, explain the behavior of such an alloy system in terms of superparamagnetism of anisotropic magnetic clusters, there are some discrepancies in the details. To our knowledge, the linear behavior of C_p(T) over as wide a temperature range as 2-12 K in such a superparamagnetic system is unique. © 1987.