Особенности магнитной структуры поликристаллов Y-=SUB=-3-=/SUB=-Fe-=SUB=-5-=/SUB=-O-=SUB=-12-=/SUB=-, синтеризованных методом радиационно-термического спекания

The Mössbauer spectroscopy (MS) method was used to study polycrystalline iron yttrium garnet (YIG) samples synthesized by radiation thermal sintering (RTS) technology and by standard ceramic technology (CT). The best option for decomposing the MS spectra of the objects of study was selected, which is a model of the experimental spectrum with five sextets. An additional fifth sextet is caused by Fe3 + ions, surrounded by oxygen vacancies which lead to distortion of the Fe tetrahedra which reflected by an increase in the quadrupole splitting of Fe3+. An increase in the density of s-electrons on Fe ions in distorted tetrahedra lead to a decrease in the isomeric chemical shift δ of Fe ions up to a values closed to the δ value for Fe4+ ions. It was shown that the optimal crystalline structure realizes for Y3Fe5O12 polycrystals upon sintering by RTS method in the temperature range of 1350–1400 ° C for a time from 40 to 60 min.

Aging Processes in Films of Iron-Yttrium Garnet Implanted by Boron Ions

Based on the results of X-ray structural analysis, changes in the crystalline structure that occurred during 15 years in surface layers of epitaxial films of iron-yttrium garnet implanted by B+ ions were studied. The processes that occur during the B+ ion implantation of in ferrite-garnet films, and the processes that accompany the low-temperature aging of ion-implanted films are considered. Strain profiles were determined from the experimental rocking curves, obtained immediately after ion implantation and after 15 years. It was found that the value of relative maximum deformation of surface layers decreases at constant thickness of the disturbed layer.

Магнитные взаимодействия на границе оксидный ферромагнетик/ферромагнитный интерметаллид

The magnetic properties of heterostructures consisting of two films are investigated: the upper layer is rare-earth intermetallic superlattices consisting of exchange-coupled TbCo2 / FeCo layers, and the lower layer, either epitaxially grown La0.7Sr0.3MnO3 (LSMO) manganite optimally doped with strontium, or an epitaxial film of an iron-yttrium garnet Y3Fe5O12 (YFO). The material (TbCo2 / FeCo) n (TCFC) provides giant magnetostriction, a large value of the magnetomechanical coupling coefficient, controlled induced magnetic anisotropy, and spin-orientational transitions induced by a magnetic field or elastic stresses. Experimental studies have shown that the interlayer interaction of the heterostructure TCFC / LSMO has an antiferromagnetic character. An increase in the FMR line width in the structures was ob-served, caused by the spin current flowing through the interface between two films. In the TCFC/YFO heterostructure, an electric voltage induced in the TCFC intermetallic film was observed, caused by the reverse spin Hall effect under ferromagnetic resonance conditions.

Influence of Structural Defects in Epitaxial Ferrite-Garnet Films on their Magnetic Properties

The study of defects observed in substrates with gadolinium gallium garnet (GGG) with orientations (110), (100) and (111) and in epitaxial films grown of iron-yttrium garnet (YIG) were investigation. It is shown that the line width ferromagnetic resonance strongly depends on the presence of defects in YIG films. It was established that the highest quality and minimal magnetic losses have YIG films with a thickness of 2...8 mm grown on GGG defect-free substrates with orientation (111), which were grinding and polishing the surface to 14 grade purity.