Effect of nanocrystallization of magnetic amorphous ribbon on thermoelectric and magnetic properties

Abstract

Fe78Si9B13 ribbons with controlled size and uniform distribution of magnetic nanoparticles are prepared by annealing of its amorphous precursor. It is found that Fe nanograins precipitate from the matrix after annealing treatment. When the grain size is smaller than 60 nm, the samples’ electrical conductivity and Seebeck coefficient increase simultaneously with the increase of grain size. When the grain size is larger than 100 nm, the electrical conductivity and Seebeck coefficient decrease simultaneously. The maximum power factor can reach about 0.58 mW·m−1·K− 2@575 K for the sample annealed at 833 K for 20 min. A planar thermoelectric power generation device is successfully fabricated using the Fe78Si9B13 ribbon with the best thermoelectric performance. At a temperature difference of 71.4 K, the maximum output power of the thermoelectric device can be about 569 nW, and the maximum open circuit voltage is about 5.3 mV.