Mechanical and thermoelectric properties of Zn4Sb3 and Zn4Sb3+Zn directly synthesized using elemental powders
Direct synthesis using elemental powders has been used to produce single-phase polycrystalline ε-Zn4Sb3 specimens as well as composite specimens having ε-Zn4Sb3 (majority phase) and Zn (minority phase). The effect of the Zn phase on the elastic, thermoelectric and mechanical properties was investigated in this alloy system. Thermoelectric properties of single-phase Zn4Sb3 at an ambient temperature are comparable to the published data for the sample prepared by a hot-pressing of ingot-melted alloy powders. Transport properties at room temperature were also evaluated. In addition, Young’s modulus and the bulk modulus of polycrystalline Zn4Sb3 were measured using a resonant-ultrasonic technique. The fracture toughness in this alloy system was determined by measuring the length of cracks that formed at the corners of pyramidal indentations used for hardness tests. It is shown that the addition of Zn increases the fracture toughness, but this is achieved at the cost of reducing the thermoelectric figure of merit.
Keywordsdirect synthesis thermoelectric Young’s modulus fracture toughness Zn4Sb3
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