P.B. Terentev

Magnetocrystalline anisotropy of Er2(Fe1 − xVx)17 compounds

The magnetic properties and magnetic anisotropy of the Er2(Fe1−xVx)17 compounds (with x = 0–0.05) have been studied. The Curie temperature (TC) of the compounds has been found to increase as the vanadium concentration increases. It has been shown that the Er2(Fe1 − xVx)17 compounds have the easy-plane anisotropy in the temperature range from, 77 K to TC. Magnetization curves have been measured and the temperature dependences of the K1 and K2 anisotropy constants have been calculated. Contributions from the Er and Fe magnetic sublattices to the magnetic anisotropy constants were distinguished. An analysis of the obtained data allowed us to conclude that the cause for the existence of first-order magnetization processes in Er2Fe17 at low temperatures is a positive contribution from the Er sublattice to K1 and a negative contribution from it to K2.

Magnetic properties of the TbNi2Mnx (0 ? x ? 1) cubic structure compounds

The structure and magnetic properties of TbNi2Mnx compounds have been studied by the X-ray and neutron powder diffraction, magnetization and magnetostriction measurements. It was found that the compounds for x < 1 crystallize in a cubic MgCu2 Laves phase structure, in spite of the R to 3d-metal ratio changes from 1:2 to 1:3. TbNi2Mn shows a superstructural ordering (F3m space group). Magnetic measurements revealed a substantial growth of the Curie temperature from 29 K for TbNi2 up to a maximum value of 160 K for TbNi2Mn0.5. Monotonous decrease of the magnetization, magnetostriction and increase of the coercivity are observed with the Mn alloying. The obtained data are interpreted assuming the formation of a magnetic moment at Ni site and a non-collinear arrangement of the Tb-ion magnetic moments.