Pressure induced structural, electronic topological, and semiconductor to metal transition in AgBiSe2

• DOI: 10.1063/1.4966275
• Publication Date: 2016-10-26T17:00:17Z
• Authors: V. Rajaji; Pallavi S. Malavi; Sharma S. R. K. C...; Y. A. Sorb; Utpal Dutta; Satya N. Guin; B. Joseph; Swapan K. Pati; S. Karmakar; Kanishka Biswas; Chandrabhas Narayana
• Keywords: Ambient pressure

We report the effect of strong spin orbit coupling inducing electronic topological and semiconductor to metal transitions on thermoelectric material AgBiSe2 at high pressures. The synchrotron X-ray diffraction Raman scattering measurement provide evidence for a pressure induced structural transition from hexagonal (α-AgBiSe2) rhombohedral (β-AgBiSe2) relatively very low around 0.7 GPa. sudden drop in electrical resistivity clear anomalous changes line width A1g Eg(1) modes 2.8 GPa was observed suggesting transition. On further increasing pressure, dependence phonon (A1g Eg(1)) frequencies widths along with temperature dependent show above 7.0 β-AgBiSe2. First principles theoretical calculations reveal that metallic character β-AgBiSe2 is mainly due redistributions density states (p orbitals Bi Se) near Fermi level. Based its multiple transitions, we propose potential candidate good performance switches pressure.