High pressure X-ray diffraction studies on Bi$_{2-x}$Sb$_{x}$Te$_{3}$ (x=0,1,2) materials

Recently Bi$_{2}$Te$_{3}$ based thermoelectric materials have gained importance due to their high thermoelectric figure of merit in thin films [3]. Pressure tuning of the thermoelectric figure of merit has been reported for several materials [1],[2]. In order to investigate the bulk properties of Bi$_{2}$Te$_{3}$, Sb$_{2}$Te$_{3}$, and their solid solution in detail, we have performed structural studies up to 20 GPa. Our diffraction results show that all three compounds transform from the ambient pressure structure to a high pressure phase between 5 and 7 GPa. Details of the results will be discussed in this presentation. [1]Chen, G., Dresselhaus, M.S., Dresselhaus, G., Fleurial, J.-P., and Caillat, T. \emph{Recent developments in themoelectric materials}. International Materials Reviews, \textbf{48}, 45-66 (2003). [2]Rowe, D.M. \emph{CRC Handbook of Thermoelectric Materials}. CRC Press, 1995. [3]Venkatasubramanian, R., Silvola, E., Colpitts, T., and O'Quinn, B. \emph{Thin-film thermoelectric devices with high room-temperature figures of merit}. Nature, \textbf{413}, 597-602, 2001.