Suppression of spin fluctuations and enhancement of the Curie temperature in compounds of the Sm2Fe17 type by introduction of atoms of nonmagnetic elements

The possibility of a Curie point increase is investigated for compounds R2Fe17 as promising materials for permanent magnets. It is shown that temperature dependences of magnetic properties of Sm2Fe17 and Y2Fe17 base compounds are determined by electron spin density thermal fluctuations. Intraatomic interaction of electrons results in local magnetic moments and in ferromagnetic ordering, at the same time this interaction is responsible for high local d-electron spin susceptibility promoting (as the temperature increases) the occurrence of strong spin fluctuations which cause the magnetization to increase and give rise to the transition into a disordered paramagnetic state. The introduction of nonmagnetic element atoms (H, N, C, Al, Si) results in the suppression of spin fluctuations and may lead to a considerable increase of Curie temperature in the ternary compounds