Magnetic properties around quantum critical point of CePt1-xRhx

In order to investigate magnetic properties around a quantum critical point of CePt1-xRhx alloys, we have performed the ac-susceptibility (chi(ac)) measurements with field frequency ranging from omega/2 pi = 0 (dc magnetization) to 1113 Hz for temperature down to 100mK on polycrystalline CePt1-xRhx (x = 0.5, 0.6). The in-phase component of chi(ac) exhibits a pronounced peak at T-f. The peak magnitude and T-f show significant field-frequency dependence. In addition, a staircaselike hysteresis loop of magnetization was observed below 200mK. From the dynamical analyses of chi(ac) we suggest that CePt0.5Rh0.5 and CePt0.4Rh0.6 can be described as cluster-glass systems. (C) 2009 Published by Elsevier B.V.