Electronic states of single crystal CeAl2 near the pressure-induced quantum critical point

The electrical resistivity and magnetoresistance (MR) of single crystal CeAl2 have been measured up to 8 and 3.2 GPa, respectively. The magnetic part of the electrical resistivity rho(mag) increases as temperature decreases until it shows two maxima around 5 K(=T-1) and 63 K(=T-2) at ambient pressure. As pressure increases, T-1 and T-2 decrease up to 2 and 3 GPa, respectively, but they begin to increase above these pressures. MR changes from negative to positive with increasing pressure. It is suggested that Kondo temperature T-K increases as pressure increases. Above 3 GPa, Fermi-liquid behavior obeying T-2 dependence of the electrical resistivity is observed and the coefficient of T-2 dependence diverges around 2.7 GPa. The Neel temperature of CeAl2 at ambient pressure is 3.8 K(=T-N) and it is suppressed to zero around 2.7 GPa. In the pressure range of 2.5 GPa <= 5P <= 2.7 GPa, rho(mag)(T) deviates largely from the normal Fermi-liquid behavior, which suggests the so-called non-Fermi-liquid behavior around 2.7 GPa. Pressure-induced superconductivity was not observed down to 50 mK around 2.7 GPa.