Silver - Bismuth - Selenium

Rainer Schmid-Fetzer

Introduction

There are many studies devoted to the ternary semiconducting compound AgBiSe₂. Samples were prepared from the constituent elements in evacuated silica tubes, heated to 1000°C, quenched and studied by DTA and powder X-ray diffraction [58Wer]. The accepted melting point is 765°C [58Wer]; other values are 762°C [58Zhu], 792°C [59Dud], 760°C [66Hir] and 768°C [68Cam]. AgBiSe₂ exists in three modifications (α'', α' and α) and the temperature for the transition α''/α' is given as 287°C [58Wer], 298°C [59Dud], 287.1°C [68Cam] and 285-325°C [66Hir]. The transition α'/α is most probably of a higher order than first; it is observed at about 120°C [58Wer] and involves only a slight atomic rearrangement [59Gel]. However, [68Cam...