MAGNETIC AND M?SSBAUER SPECTRA STUDY OF YTi(Fe 1-x Co x ) 11

YTi(Fe 1-x Co x ) 11 crystallizes in the ThMn 12 -type tetragonal structure, with x ranging from 0.0 to 1.0, the Curie temperature increases with the increase of Co content. In order to understand the relation between magnetic properties and microst-ructure of these compounds, we studied their M?ssbauer spectra. The M?ssbauer effect measurements were carried out at room temperature on YTi(Fe 1-x Co x ) 11 , with x equal to 0.0, 0.2 and 0.4. The best fits confirm that Co atoms preferentially occupy the j and f sites. The hyperfine fields of the measured samples reach a maximum at x = 0.2,which is in agreement with the results of magnetic measurements. By comparing the experimental results of M?ssbauer spectra of YTi(Fe 1-x Co x ) 11 , Y 2 (Fe 1-x Co x ) 14 B and YTi(Fe 1-x Ni x ) 11 , we analyze the difference of the 3d band structure between YTiFe 11 , and Y 2 Fe 14 B.