Searching for the Slater transition in the pyrochlore Cd<inf>2</inf>Os<inf>2</inf>O<inf>7</inf> with infrared spectroscopy

TitleSearching for the Slater transition in the pyrochlore Cd2Os2O7 with infrared spectroscopy
Publication TypeJournal Article
Year of Publication2002
AuthorsWJ Padilla, D Mandrus, and DN Basov
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume66
Issue3
Start Page351201
Pagination351201 - 351205
Date Published07/2002
Abstract

Infrared reflectance measurements were made on the single crystal pyrochlore Cd2Os2O7 in order to examine the transformations of the electronic structure and crystal lattice across the boundary of the metal-insulator transition (MIT) at TMIT=226 K. All predicted IR active phonons are observed in the conductivity over all temperatures and the oscillator strength is found to be temperature independent. These results indicate that charge ordering plays only a minor role in the MIT and that the transition is strictly electronic in nature. The conductivity shows the clear opening of a gap with 2Δ=5.2kBTMIT. The gap opens continuously, with a temperature dependence similar to that of Bardeen-Cooper-Schrieffer (BCS) superconductors, and the gap edge having a distinct σ(ω) ∼ ω1/2 dependence. All of these observables support the suggestion of a Slater transition in Cd2Os2O7.

Short TitlePhysical Review B - Condensed Matter and Materials Physics