Substitution effect on the multipolar transitions in Pr(FexRu1-x)4P12

Substitution effect has been studied for the transition metal site on both of the metal-insulator transition in PrRu4P12 and the anomalous nonmagnetic transition (probably of multipolar origin) in PrFe4P12 by mutual alloying. It has been found that both of the transitions are significantly suppressed by the substitution. This observation supports the scenario that the expected Fermi-surface-nesting instability is an essential ingredient for both of the orderings. In the nonordered state, logarithmic temperature dependence in the electrical resistivity indicative of Kondo-like scatterings has been found only around the high Fe concentration, suggesting important roles of the Fe 3d electrons for the strongly correlated behavior. (c) 2006 Elsevier B.V. All rights reserved.