Pressure effect on antiferromagnetic ordering in UPb

Haga, Yoshinori   ; Yamamoto, Etsuji  ; Onuki, Yoshichika; Nakashima, Miho*; Aoki, Dai*; Onuki, Yoshichika*; Hedo, Masato*; Uwatoko, Yoshiya*

Uranium intermetallic compounds UX (X = Si, Ge, Sn, Pb) form a ariety of magnetic properties including Pauli paramagnetism in USi and UGe, spin fluctuations in USn and antiferromagnetism in UPb. Among them, UPb is an antiferromagnet below the Nel temperature 32 K with a large electronic specific heat = 110 mJ/Kmol. In this study we present the electrical resistivity measurement under high pressure up to 8 GPa. We found that at low pressure increases with increasing pressure. It has a maximum value 36 K at 3 GPa, then decreases with increasing pressure.In addition we observed an additional resistive anomaly followed by a steep decrease in resistivity below under pressure.The maximum pressure 8 GPa in the present study was not enough to suppress the antiferromagnetic transition.The critical pressure is estimated to be around 12 GPa.