Synthesis and Measurement of the Thermoelectric Properties of Multiphase Composites: ZnSb Matrix with Zn^sub 4^Sb^sub 3^, Zn^sub 3^P^sub 2^, and Cu^sub 5^Zn^sub 8

Issue Title: 2012 International Conference on Thermoelectrics. Guest Editors: Ryoji Funahashi, Donald Morelli, Lasse Rosendahl, and Jihui Yang We synthesized a series of samples with composition around 52 at.% zinc (Zn), 44 at.% antimony (Sb), 4 at.% phosphorus (P), and up to 3 at.% copper (Cu) by melting the elements and subsequent annealing. This resulted in dense and almost crack-free samples. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) revealed composites with a majority phase of ZnSb containing varying amounts of Zn^sub 3^P^sub 2^ and Cu^sub 5^Zn^sub 8^, in addition to Zn^sub 4^Sb^sub 3^ in some of the samples. We measured the Seebeck coefficient, electrical conductivity, and thermal conductivity as a function of temperature. The thermoelectric performance tended to improve with increasing Cu content. At Cu content of 2 at.%, a reduced resistivity allows for the highest dimensionless figure of merit, with a maximum zT value of 0.18 at around 573 K.[PUBLICATION ABSTRACT]