Influence of carbon introduced by arc melting on the structural and magnetic properties of RFe12−xVx (R = Y and Dy)

Carbon was introduced by arc melting into RFe_12−xV_x compounds, where R = Y or Dy and x = 2, 3 or 4, and its effects on the crystallographic and magnetic properties of these intermetallics were investigated by X-ray, magnetostatic and Mössbauer effect measurements. Experimental results show that the carbon atoms prefer the 4d sites to the 2b sites, or occupy the sites reserved for Fe atoms in the ThMn₁₂-type crystal structure. Carbon solution increases with increasing vanadium concentration, giving rise to an effect opposite to that of vanadium. An increase in vanadium content causes an increase in the cell volume and a linear decrease in Curie temperature and in the Fe magnetic moment, whereas the addition of carbon leads to a reduction in unit volume while maintaining a high T_c and enhancing the Fe magnetic moment despite decreasing iron content in the samples.