Control of crystallographic texture and grain size in bulk thermoelectric materials through constrained deformation

摘要

New methods for improving thermoelectric properties of bismuth telluride based materials are described. Constrained deformation, such as by canned/sandwich, or encapsulated, rolling and plane strain channel die compression, particularly at temperatures above 80% of the melting point of the material on an absolute temperature scale, changes the crystallographic texture and grain size to desirably increase the values of both the thermoelectric power factor and the thermoelectric figure of merit ZT for the material.