CRYSTALLOGRAPHIC AND MAGNETIC-STRUCTURE OF THE ITINERANT-ELECTRON ANTIFERROMAGNETS MN3-XTXSI (T=CR, FE)

The effects of alloying on the itinerant-electron antiferromagnet Mn3S i have been investigated by substituting Cr or Fe for Mn. Mn3-xTxSi (T = Cr, Fe) alloys have the Heusler-type crystal structure for 0 less t han or equal to x less than or equal to 0.2 of Cr-substitution and for the full range of Fe-substitution, and show antiferromagnetism for th e whole range of present investigation: 0 less than or equal to x less than or equal to 0.2 for Cr- and 0 less than or equal to x less than or equal to 1.0 for Fe-substitution. Incommensurate spin orderings are observed for 0 less than or equal to x less than or equal to 0.1 on b oth sides of the substitution.