The dependence of the microstructure and thermoelectric properties of germanium-doped higher manganese silicide crystals

Resumo

The reason why manganese monosilicide inclusions are formed during the growth of higher manganese silicide (HMS) crystals has not been studied in detail so far. Changes in the amount and density of these inclusions are greatly influenced by dopants. In this study, the structure of HMS crystals with various contents of germanium as a doping element is examined. It is found that raising the germanium content to 1 at % results in the fragmentation of layered manganese monosilicide inclusions and, simultaneously, leads to significant changes in the thermoelectric properties of HMS crystals. The results of the microstructural analysis of HMS crystals in relation to the germanium concentration may be of use for understanding the mechanism by which the manganese monosilicide phase is formed during the growth of higher manganese silicide crystals.