Magnetic measurement on uranium ferromagnetic superconductor UGe

Tateiwa, Naoyuki   ; Haga, Yoshinori   ; Yamamoto, Etsuji  

Many studies have been done fro the co-existence of the superconductivity and the ferromagnetism in UGe, URhGe, and UCoGe. In this presentation, we will show our results of the magnetization measurements under pressure obtained with our ceramic anvil high pressure cell. The superconducting transition temperature becomes maximum at around a phase boundary of the ferromagnetic phases FM1 and FM2. We have found that the pressure dependence of the width of the spin fluctuation spectrum also exhibits a peaked structure around the boundary. This suggests a correlation between the superconductivity and the ferromagnetic fluctuations developed around the boundary. We will mention the Rhode-Wohlfarth relation under pressure.