Thermal stability of cluster structure in Bi_xSn_1−xmolten alloys in vicinity of eutectic point

Abstract

Structure of liquid Bi x Sn 1Àx molten alloys has been studies in the vicinity of eutectic point at temperatures of complete melting and above by 100 K. It is shown that the structure parameter concentration dependences reveal the deviation from linear function with extremum points at eutectic composition. Such features exist also at higher temperatures. The reason of untypical behaviour of structure parameters is supposed to be attributed to the existence of two kinds of clusters with Sn-and Bi-like structures.

The Transformation of the Structure at Heating and Mechanism of Thermal Expansion of Sn-Bi Eutectic Alloy

“…Particularly the data on structure, obtained within concentration range 25-60 at. % Bi, allowed to conclude the existence of few kinds of clusters (Sn 75 Bi 25 , Sn 64 Bi 36 , Sn 53 Bi 47 and Sn 40 Bi 60 ), which are stable at temperatures close to melting points [18]. According to data of [19] the temperature increasing leads to rearrangement of atoms in clusters Sn 53 Bi 47 , whose concentration corresponds the eutectic alloy.…”

“…The structure of majority of liquid metals and their alloys, including Sn-Bi binary melts, is studied in detail by means of diffraction methods [16] as well as by measurements of structure-sensitive physical properties. Structure parameters, obtained from diffraction studies and physical properties measurements for Sn-Bi binary system are available within wide concentration range and at different temperatures [17][18][19][20].Analysis of main publications allowed to note the existence of preferred interaction between unlike kind atoms that leads to formation of dimmers [17] and clusters, which are stable within wide temperature range. Particularly the data on structure, obtained within concentration range 25-60 at.…”