Thermoelectric properties of the unfilled skutterudite FeSb3 from first-principles and Seebeck local probes

Abstract

Using a combination of first-principles calculations and experimental transport measurements, we study the electronic and magnetic structure of the unfilled skutterudite FeSb3. We employ the hybrid functional approach for exchange-correlation. The ground state is determined to be anti-ferromagnetic with an atomic magnetic moment of 1.6 μB/Fe. The N ́eel temperature TN is estimated at 6 K, in agreement with experiments which found a paramagnetic state down to 10 K. The ground state is semiconducting, with a small electronic gap of 33 meV, also consistent with previous experiments on films. Charge carrier concentrations are estimated from Hall resistance measurements. The Seebeck coefficient is measured and mapped using a scanning probe at room temperature that yields an average value of 38.6 μVK−1, slightly lower than the theoretical result. The theoretical conductivity is analyzed as a function of temperature and concentration of charge carriers.