Papers by Author: G.V. Ivanova

Abstract: Structure and mechanical properties of high-strength alloys on the basis of the Fe-Cr-Co system with W, Ga, Cu and Al additives have been investigated by the Mossbauer technique. It is shown that the magnitude of yield strength is independent of the dopants, whereas the relative elongation is controlled by the process of phase separation in the alloys which is dependent on additions.

Abstract: Spin-reorientation transitions in intermetallic (Pr1-xSmx)Fe8Ga3C compounds with the tetragonal BaCd11-type structure have been investigated. The magnetic phase diagram has been proposed for these compounds based on magnetic and X-Ray diffraction studies using their nanocrystalline ribbons and powders aligned in a magnetic field. In the concentration range 0 ≤ x ≤ 0.4 the compounds exhibit an «easy-plane» anisotropy at all temperatures of the magnetically ordered state. The magnetic anisotropy of the compounds with 0.5 ≤ x ≤ 1 is of the «easy-cone» type. The SmFe8Ga3C compound with the highest Sm content is a uniaxial ferromagnet with no indications of a spin-reorientation transition below its Curie temperature.

Abstract: We have synthesized a novel intermetallic compound PrFe8Ga3C and studied its structure and magnetic properties. X-ray diffraction analysis revealed that the compound possesses a tetragonal BaCd11-type structure (space group I41/amd). In this structure Ga atoms occupy the same sites as Fe atoms with preferably filling the 4(b) site. Magnetization curves have been measured on the aligned powder samples. Below the Curie temperature TC = 400 K the easy magnetization direction was found to orient within the (100) plane. At 80 K the compound has a spontaneous magnetization of 97 emu/g and anisotropy constant of 4.2107 erg/cm3. At room temperature these values reduce to 78 emu/g and 4.7106 erg/cm3, respectively.

Abstract: The structure, mechanical and magnetic properties have been studied for Fe-Cr-Co-based hard magnetic alloys with W and Ga additives, subjected by the quenching and post-deformation hardening. The alloys combine the properties of the hard magnetic material with outstanding mechanical strength and plasticity. Using X-ray and electron microscopy analysis, the reasons and conditions of formation of these properties have been determined.