Physics Dept-MtSE Joint Seminar

October 12, Thursday (*SPECIAL DAY*)

V3d–O2p Hybridization Anomaly at Crossover Temperature in V₂O₃

Dr. Chang-Yong Kim

Canadian Light Source Inc., Canada

(Condensed Matter/materials Physics, Host: Tyson)

*SPECIAL TIME: 2:45pm-3:45pm with 2:30pm tea time

Room: ECE 202

The V₂O₃ has been known as typical Mott insulator with first order metal-insulator transition at 150 K accompanying structural transition from monoclinic to corundum phase. In the metallic phase, conducting electron state appears at the Fermi level. As temperature increases further, conductivity degrades continuously with a sudden drop around 450 K. Above this crossover temperature (~ 450K) distinction between metal and insulator disappears. Theoretical calculation reports that incoherent electron spectral weight increases around the Fermi level as the coherent electron quasiparticles are destroyed as temperature approaches crossover regime. From our recent study of X-ray induced vanadium L₂₃M₂₃M₄₅ Auger spectra we found that O 2p contribution to V L₂₃M₂₃M₄₅ Auger spectra through hybridization with V 3d has anomaly at the crossover temperature. Possible origins of the hybridization anomaly will be discussed in conjunction with previously reported anomalies in the lattice parameters and elastic constants.