Microstructure and thermoelectric properties of the medium-entropy block-textured BiSbTe₁.₅Se₁.₅ alloy

Abstract

Medium-entropy BiSbTe1.5Se1.5 alloy has been prepared by self-propagating high-temperature synthesis (to prepare a starting powder with desired composition and structure) and spark plasma sintering (to prepare block-textured samples). Under texturing, a partial ordering of grains, which is typical for Bi2Te3-based alloys, takes place resulting in forming a lamellar grain structure. Lamellar sheets are not continuous for whole volume of the textured sample. There are blocks with continuous lamellar sheets of some definite orientation, but the orientations of the sheets in neighboring blocks are different from each other. Forming the block-textured structure can be related to specific features of the starting powder