Electric properties of Co-doped and Ni-doped beta-FeSi2

The electrical resistivity and Hall effect of Co-doped and Ni-doped beta-FeSi2 were quantified in the temperature range between 80 and 300 K. The results showed that the solid solution Fe1-xCoxSi2 is n type over the entire temperature range investigated, whereas the solid solution Fe1-yNiySi2 exhibited n type characteristics at temperatures beyond 160 K and p type tendencies below 160 K. At 300 K, the carrier concentration of Fe1-xCoxSi2 is one level higher than that of Fe1-yNiySi2.