Silver - Bismuth - Tellurium

Rainer Schmid-Fetzer

Introduction

The ternary semiconducting compound AgBiTe₂ was studied by thermal analysis, metallographic and X-ray techniques [63Ste] on samples prepared from the elements. A congruent melting point at 555°C±3°C is accepted [63Ste]. Lower values of 542°C [58Wer] and 520°C [58Zhu] may correspond to supercooling. The compound decomposes at 443°C according to the eutectoid reaction 2AgBiTe₂ ↔ Ag₂Te + Bi₂Te₃ as determined from a strong thermal arrest and confirmed by metallographic and X-ray evidence [63Ste]. This decomposition was observed by [58Wer] at 428°C who also mention a solid solubility of Ag in the Bi₂Te₃-phase. [58Zhu] report a transition in AgBiTe₂ near 130°C. However, this effect is most probably due to the α'/α-tran...