Comparative Study of the Thermoelectric Properties of Amorphous Zn41Sb59 and Crystalline Zn4Sb3

The alloy Zn41Sb59 was synthesized by high-pressure techniques and its bulk amorphous nature at ambient conditions confirmed by X-ray powder diffraction and electron microscopy studies. Electrical resistivity, thermopower, and thermal conductivity of Zn41Sb59 were measured in a temperature range from 6 to 350 K. Zn41Sb59 is a semiconductor and resistivity data suggest an activation energy of about 0.25 eV above 250 K. The thermopower is positive and increases with increasing temperature. Room-temperature values for the resistivity and thermopower are 8 Ω cm and 300 μV/K, respectively. The temperature dependence of the thermal conductivity is characteristic for amorphous solids and continuously increasing from 0.08 W/(m K) at 6 K to 0.19 W/(m K) at room temperature. Comparison of the thermal conductivity of Zn41Sb59 with the thermal lattice conductivity of the crystalline thermoelectric material β-Zn4Sb3 reveals a remarkable resemblance, justifying the classification of the latter as a phonon-glass material.