ICT2014 Abstracts

Zintl phases containing antimony are well known thermoelectric materials. This work focuses on the investigation of high temperature thermoelectric properties of some selected ternary 1-2-2 Zintl phases based on tin or silicon. With some exceptions these compounds of the composition ATM₂Tt₂ (A = alkaline earth or rare earth metal; TM = transition metal; Tt = group 14 element) crystallize in the ThCr₂Si₂ structure type. Magnetic properties were widely studied but thermal transport properties are mostly unknown.

We are interested in the thermoelectric potential of compounds with the general composition ATM₂Tt₂. Synthesis of the materials is done via arc melting technique and subsequent annealing at elevated temperatures. The samples are characterized, densified using spark plasma sintering and investigated with respect to their thermoelectric properties. Characterization methods include X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Furthermore high temperature thermal analysis, measurements of the Seebeck coefficients as well as of the electrical and thermal conductivities were done.

The results will be discussed as well as the influence of structure, chemical composition and electronic situation.