T. Zhao

Magnetic properties of rare-earth compounds of the RCo10Mo2 type

acad sinica,inst met res,shenyang 110015,peoples r china. acad sinica,inst phys,beijing 100080,peoples r china.;zeng, dc (reprint author), univ amsterdam,van der waals zeeman lab,valckenierstr 65,1018 xe amsterdam,netherlands

Structural and magnetic properties of RFe10Mo2 and RFe10Mo2N

The structural and magnetic properties of and have been studied by x-ray diffraction and high-field magnetization measurements on free-powder or magnetically aligned samples. The lattice of expands anisotropically upon nitrogenation and the volume of the unit cell increases by 2.9 - 4.0%. The rare-earth element dependence of lattice expansion is found to be just opposite to that of the Curie temperature. The saturation magnetization of increases after the introduction of nitrogen. The abnormally large values of magnetization for some heavy-rare-earth compounds imply that a non-collinear moment configuration in the absence of an external field may exist in these compounds.

Magnetocrystalline anisotropy of SmFe12 − xMox compounds with x = 0.5, 1.0, 1.5, 2.0 or 3.0

Abstract The magnetic anisotropy fields of SmFe12 − xMox compounds with x = 0.5, 1.0, 1.5, 2.0 or 3.0 were determined up to the Curie temperature using the SPD technique. An anomalous increase in the magnetization was detected at 4.2 K in the compounds with x = 1.0, 1.5 or 2.0 by measuring the magnetization on magnetically aligned samples with external fields applied parallel or perpendicular to the alignment direction.

Structure and magnetic properties of R(FeVB)12 compounds

Stable R(FeVB)(12) compounds (R=Nd, Sm, Y) with the ThMn12-type tetragonal structure have been prepared. The Curie temperatures of these compounds are enhanced compared with the boron-free compounds. In some of these compounds the saturation magnetization at 4.2 K is also increased. A spin reorientation is observed at 130 K in Nd(FeVB)(12). FOMP transitions occur at 4.2 K in both Sm(FeVB)(12) and Nd(FeVB)(12) compounds, with onset fields of 11.5 T and 2.2 T, respectively.

Magnetic properties of Er(Fe,Ni)10Si2 compounds

Abstract The magnetic properties of ErFe 10-x Ni x Si 2 compounds with x = 0,2,3,3.5,4,4.5 have been studied by measuring magnetization curves of free-powder samples at 4.2 K in fields up to 38 T and by measuring the temperature dependence of the AC susceptibility in the temperature range 4.2–300 K. In these compounds, the antiparallel alignment of the Er-and 3d-sublattice moments is broken in the applied fields and a bending process of the two sublattice magnetization is observed. An oscillatory behaviour of the magnetization is found which can be explained by taking into account the magnetic anisotropies of both the Er- and the 3d-sublattice up to K 4 . Below room temperature, a spin-reorientation is observed in all compounds. The spin-reorientation temperature increases with increasing Ni content.

Magnetic properties of ThMn12-type (Er,Y)Co10Mo2 compounds

High-field magnetization measurements at 4.2 K have been performed up to 35 T on free-powder samples of Er1-xYxCo10Mo2 compounds with x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0. The results have been analyzed in a two-sublattice mean-held model to determine the inter-sublattice molecular-field coefficients and the magnetic moments per cobalt atom. Spin-reorientation transitions have been investigated in these compounds between 4.2 K and room temperature by measuring the AC susceptibility. The easy direction of the magnetization in the compounds is found to change from c-axis at high temperature to basal plane at low temperature. The spin-reorientation temperature decreases with decreasing Er concentration.

Crystallographic and magnetic properties of ternary nitrides of the type RCo10Mo2Nx

Abstract The magnetic and crystallographic properties of rare earth-based interstitial nitrides of the type RCo 10 Mo 2 N x (R = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Y) were investigated by means of X-ray diffraction, high-field measurements and a.c. susceptibility measurements. From X-ray diffraction it was derived that the interstitial hole filling remains substantially below one nitrogen atom per formula unit RCo 10 Mo 2 N x . We determined the easy magnetization direction in these compounds and found that the Co sublattice anisotropy favours an easy moment direction along the c -axis. The rare earth sublattice anisotropy is governed by a positive value of the second-order crystal field parameter. The large uniaxial anisotropy and the atomic disorder favour the occurrence of a thermally activated intrinsic coercivity in some of the nitrides.