Some Magnetic Properties of YTiFe $_{11-{\rm x}}$ Si $_{\rm x}$ C Carbides

The effect of carbonation on the structure and the magnetic properties of polycrystalline YTiFe_11-x Si_x (0 les x les 2) have been investigated by means of x-ray diffraction (XRD) at room temperature and magnetic measurements at low temperature. The alloys were prepared by typical induction melting and the carbonation was performed by solid-solid reaction. The cell volume of ThMn₁₂ structure and the Curie temperature increase after carbonation, but decrease with Si content. The saturation magnetization and the magnetic moment were determined from parallel magnetic isotherms using the common law of approach to saturation. The experimental average magnetic moment per atom decreases with Si content. The comparison of experimental 3d-magnetic moment with the calculated values from the magnetic valence approximation (MVA) shows a strong ferromagnetism, induced by carbonation. The XRD patterns of magnetically oriented powder show an uniaxial anisotropy for YFe_11-xSi_xTiC. The second and fourth order magnetocrystalline constants, K₁ and K₂ have been determined using an analytical interpretation, based on the statistical model, of perpendicular magnetization isotherms of the magnetically aligned powder samples. The magnetocrystalline constants and anisotropy field have been determined versus temperature and composition.