Search

The electrical resistivity and magnetoresistance (MR) of CePtSi2 have been measured under high pressure in order to clarify the electronic state around TN ∼ 0 K. ρmag (T) at ambient pressure, defined as ρmag = ρ(CePtSi2)-ρ(LaPtSi2), increases with decreasing temperature until it shows a maximum around 28 K(=T2) and a small shoulder around 5 K(=T1). T1 increases with applying pressure and merges into T2 around 1.0 GPa. T2 is almost constant up to 1.0 GPa, but increases rapidly with applying pressure above 1.0 GPa. Negative MR was observed up to 2.4 GPa at 4.2 K. The magnitudes of MR at 9 T are-24.5% and-7.9% at 0.1 and 2.4 GPa, respectively. By applying the Okiji-Kawakami model to the present results, it is found that the Kondo temperature TK increases with increasing pressure. The slope of pressure dependence of MR ratio at 9 T changes slightly around 1.0 GPa. These results suggest a pressure-induced crossover in the electronic states around 1.0 GPa. [ABSTRACT FROM AUTHOR]