Galvanomagnetic and Thermomagnetic Properties of Ag$_{(1-x)}$Na$_{x}$SbTe$_{2}$ Alloys

Group I-V-VI$_{2}$ alloys have intrinsically low thermal conductivity$^{1}$ on the order of 0.65 W/mK due to Umklapp phonon-phonon scattering. Combined with the high valence band density of states in AbSbTe$_{2}$, this makes this material system ideal for thermoelectric applications up to 416 K, where AgSbTe$_{2}$ undergoes a crystallographic phase transition. The partial substitution of Na for Ag is expected to address this problem. We synthesize bulk Ag$_{(1-x)}$Na$_{x}$SbTe$_{2}$ alloys and measure the evolution of the phase transition as a function of Na concentration x. The thermoelectric and galvanomagnetic properties of the alloys are also studied: based on the measurement of resistivity, Seebeck, Nernst and Hall coefficients we calculate mobilities, Fermi energies and partial carrier concentrations of holes and electrons.