ABSTRACT
PrRu4P12 is a metal at room temperature, and is known to show a metal-insulator transition at about T=60 K [2]. Several studies have been carried out to understand the mechanism of this transition. Powder x-ray roeasurements made using synchrotron orbital radiation seemed hard to detect a structural change associated with this phase transition [3]. A purely electrical phase transition is deduced to exist. However, PrL2 -edge XANES measurements suggested that Pr atom seemed almost trivalent independent of temperature [4]. Magnetic susceptibility showed no anomaly at the transition temperature. This indicates magnetic ordering is not involved in this transition [4]. Until recently the origin of this metalinsulator transition was uncertain.
