A heat capacity anomaly of the superconducting transition in a ferromagnetic superconductor UGe2

We performed the heat capacity, <f>C(T)</f>, measurement under high pressure on a ferromagnetic superconductor UGe2, in order to study the pressure dependence of the anomaly in <f>C(T)</f> associated with the superconducting transition. A clear peak appears only around a critical pressure <f>Pc*</f> where an another transition temperature <f>T*</f> becomes 0 K. This result suggests that a bulk superconducting phase exists in the narrower pressure region around <f>Pc*</f> than those clarified by previous studies. [Copyright &y& Elsevier]