Magnetic and Structural Properties of R2(Fe,M)17 Alloys with R = Pr, Tm and M = Cr, V, Ti, Nb, Zr

The effect of the partial substitution of M = Ti, V, Cr, Zr, and Nb for Fe in the Pr2Fe17 and Tm2Fe17 alloys on their structural, magnetic, and magnetocaloric properties have been studied using magnetic measurements, X-ray, and neutron diffraction. The character of substitution of Ti, V, Cr, Zr, and Nb atoms for Fe atoms, along with the differences in atomic radii of these elements, substantially affects variations of the lattice parameters and Curie temperatures of the Tm2Fe17 – xMx and Pr2Fe17 – xMx alloys. The Curie temperature of all the substituted alloys increases; the rate of the increase in the Curie temperature of the Tm2Fe17 – xMx alloys is twice that of the Pr2Fe17 – xMx alloys. The magnetic moment of iron atoms MFe and the magnetocaloric effect –ΔSM decrease for the substituted Tm2Fe17 – xMx and Pr2Fe17 – xMx alloys and become close in the case of all M.