Evaluation of the solid/liquid interface undercooling during Sn-Se Eutectic growth

Abstract

The Sn-Se eutectic solidification allows one to obtain a lamellar structure, formed by SnSe and SnSe2 compounds, which are p and n semiconducting types, respectively. The SnSe-SnSe2 eutectic composite is a promising material to be used in photovoltaic device manufacturing. In a lamellar eutectic microstructure, the main parameter, which governs many of its characteristics, is the lamellar spacing. Such a parameter is primarily a result of the undercooling at the solid/liquid interface, which depends on the growth rate and the eutectic system properties. In this work, the Sn-Se alloy corresponding to eutectic composition was studied by using DSC thermal analysis and directional solidification at several growth rates in a vertical Bridgman-Stockbarger unit. The objective of the experiments was to investigate the influence of the growth rate on the growth undercooling, as well as on the eutectic microstructure. The microstructure analysis showed that a very regular and aligned structure formed by the SnSe and SnSe2 solid phases can be produced. By using the classic eutectic growth theory developed by Jackson and Hunt, the experimental results obtained led to the evaluation of a relationship among growth rates, eutectic growth temperature and lamellar spacing

Crystal Growth of a Lamellar Sr3Ru2O7–Sr4Ru3O10 Eutectic System

“…Recently, interesting results were obtained – from the study of Sr-based layered ruthenates eutectic systems. One of the main motivations for carrying out eutectic growth is the possibility to develop in-situ composite materials where the properties of the distinct constituents merge to a variable extent into those of a single material , . The recent discovery of superconductivity at 3 K in Sr 2 RuO 4 –Ru metal eutectic crystals ,– has stimulated investigations for other eutectics, such as Sr 2 RuO 4 –Sr 3 Ru 2 O 7 , – where magnetic and superconducting properties appear to be different from those exhibited separately by the two phases , .…”

“…One of the main motivations for carrying out eutectic growth is the possibility to develop in-situ composite materials where the properties of the distinct constituents merge to a variable extent into those of a single material. 25,26 The recent discovery of superconductivity at 3 K in Sr 2 RuO 4 -Ru metal eutectic crystals 21,[27][28][29] has stimulated investigations for other eutectics, such as Sr 2 RuO 4 -Sr 3 Ru 2 O 7 , [22][23][24] where magnetic and superconducting properties appear to be different from those exhibited separately by the two phases. 24,30 In this context, Sr 3 Ru 2 O 7 -Sr 4 Ru 3 O 10 eutectic crystals, featuring a coexistence of metamagnetism and ferromagnetism, are likely to exhibit a magnetic behavior qualitatively different with respect to the corresponding single phase crystals.…”

Single‐Crystal SnSe Thermoelectric Fibers via Laser‐Induced Directional Crystallization: From 1D Fibers to Multidimensional Fabrics

“…Theoretical studies suggest that the recrystallization process is sensitive to three factors: the heating temperature, the spatial temperature gradient at the solid-liquid interface, and the solidification velocity. [12] In our method, changing the power of the laser and the fiber feed-in velocity allows easy control of these factors.…”

Laser-induced in-fiber capillary instability and material engineering

“…Previous studies have suggested that the in-fiber laser recrystallization is controlled by three factors: the heating temperature, the spatial temperature gradient 𝜕𝑇 𝜕𝑧 at the solid-liquid interface, as well as the solidification velocity [116,161]. By changing the output power of the laser together with the fiber feed-in velocity, combinations of these factors can be achieved on this system.…”

“…The recrystallization process is controlled by three factors: the heating temperature, the spatial temperature gradient at the solid-liquid interface, as well as the solidification velocity [116,161]. The main purpose of the laser recrystallization system is to provide a stable nucleation rate and sufficient duration for the single crystal interface development.…”