Microstructure control of β‐FeSi2 ceramics by rf‐plasma processing in SiH4 and GeH4 gases

The micrograins of Cr‐doped FeSi2 alloys were exposed to rf‐plasma of germane (GeH4) gas and mixture gas of germane and silane (SiH4), and then sintered. The resulting β‐Fe0.9Cr0.1Si2 (p‐type) ceramics have smaller thermal conductivities and larger electrical conductivities than untreated ones. These results suggest that the microstructure control by plasma treatment is effective for improving the thermoelectric properties of FeSi2 ceramics.