Second Phase Transition in Pyrochlore Oxide Cd₂Re₂O₇

Abstract

Evidence of another phase transition at 120 K in the metallic pyrochlore oxide Cd₂Re₂O₇, following a structural transition at 200 K and followed by a superconducting transition at 1.0 K, is obtained by resistivity, magnetoresistance, specific heat, and X-ray diffraction measurements. The results indicate unique successive structural and electronic transitions in the pyrochlore compound, revealing an interesting interplay between the crystal and electronic structures on the itinerant electron system in the pyrochlore lattice.