T. Mito, M. Otani, M. Nakamura, T. Koyama, S. Wada, H. Kotegaway, T. C. Kobayashi, B. Idzikowski, M. Reiffers, J. L. Sarrao
Acta Physica Polonica A 115(1) 47-52 2009年1月 査読有り
We studied pressure effects on YbCu5 and YbInCu4, good examples of the Yb-based compounds to investigate the nonmagnetic-magnetic transition in Yb-based strongly correlated electron systems. With increasing pressure, the low-temperature Fermi liquid state of YbCu5 is gradually suppressed, suggesting the second-order like nonmagnetic-magnetic transition around the pressure of 5-6 GPa. On the other hand, in YbInCu 4 which has a pressure-induced magnetic ordered ground state above PC = 2:45 GPa, both high-temperature paramagnetic and low-temperature intermediate valence phases are insensitive to pressure. Our results confirm the first-order nature of the transition between the intermediate valence and magnetic ordered phases with pressure.