Thermoelectric Properties Higher Manganese Silicide Containing Small Amount of Mnsivsinano‐Particles

Improved Thermoelectric Properties of Re-Substituted Higher Manganese Silicides by Inducing Phonon Scattering and an Energy-Filtering Effect at Grain Boundary Interfaces

“…The average grain size observed for a Re-free sample was ∼2 μm, while 6 atom % Re substitution drastically reduced the grain size to ∼250 nm, presumably because of the increased rate of nucleation around Re atoms in the rapid quenching process. Considering the microstructure with very fine equiaxed grains on the order of nanometers, we expected a large energy-filtering effect like that observed for a Re-free HMS and a strong phonon scattering at the grain boundaries . Modification of the fine grain structure (Figure a) was observed in annealed ribbons (Figure b), which show a diffused microstructure with an average grain size of ∼2 μm.…”

“…They studied the effect of the sintering temperature on the grain size; as the grain size was increased, the effect of energy filtering on the PF was minimized. By considering these reports, we investigated, in the previous work, the effect of carrier filtering due to secondary phases (Si/MnSi) and grain boundaries in HMSs . As a result, we derived that the energy-filtering effect at the grain boundaries might be due to the formation of Schottky barriers (Figure a), which can enhance the PF by 20–30%.…”