Electronic Phase Diagram of Mixed-Valence Gold Chloride
LIU Xiao-Jun1,2, MORITOMO Yutaka2, KOJIMA Norimichi3
1Laboratory of Modern Acoustics and Institute of Acoustics, Nanjing University, Nanjing 210093
2Department of Applied Physics, Nagoya University, Nagoya 464-8601, Japan
3Department of Pure and Applied Sciences, University of Tokyo, Tokyo 153-8902, Japan
Electronic Phase Diagram of Mixed-Valence Gold Chloride
LIU Xiao-Jun1,2;MORITOMO Yutaka2;KOJIMA Norimichi3
1Laboratory of Modern Acoustics and Institute of Acoustics, Nanjing University, Nanjing 210093
2Department of Applied Physics, Nagoya University, Nagoya 464-8601, Japan
3Department of Pure and Applied Sciences, University of Tokyo, Tokyo 153-8902, Japan
Abstract： A comprehensive electronic phase diagram is derived for mixed- valence gold chloride Cs2Au2Cl6 by means of high-pressure Raman spectroscopy. At all the temperatures investigated (100 K ≤ T ≤ 300 K), applications of pressure induce a phase transition from the mixed-valence (MV) state to a single-valence (SV) state. In the SV state, a broad Au-Cl stretching band appears at ～ 400cm-1 below ～ 200 K. We have interpreted the appearance of the band in terms of formation of the AuX-2-like local lattice distortion, or the bipolarons.
2004, Vol. 21 
