Magnetic properties of Ge substituted Ru2FeSi alloys

A systematic study of Ge substitution in Ru2FeSi alloys synthesized by the arc melting method is presented in this work. Crystallographic analysis using the Rietveld refinement technique reveals that at room temperature, all compositions of Ru2Fe(Si1−xGex) alloys with 0≤x≤1 mol%, exhibit cubic B2 structure with unit cell volume increasing from 203.3 to 212.8 Å3 as x was increased from 0 to 1 mol%. B2 structure occurs in Heusler (X2YZ) compounds due to partial disorder in the Y and Z sites. Magnetization measurements showed that Ru2FeSi is antiferromagnetic with Neel temperature of 270 K. Substitution of Ge in Si sites resulted in the development of ferromagnetism as indicated by magnetization and magnetic susceptibility data collected on the samples. Curie temperature increased from 354 K to 460 K as x was increased from 0.25 to 1.00 mol%, which shows that the ferromagnetic state becomes dominant as x is increased in the quaternary alloys.