The crystal structure data of CoxTiS2 series of compounds in a wide range of Co concentrations (0.00 < x <= 1.00) are summarized. The compounds with high cobalt concentrations (x >= 0.75) have been synthesized for the first time. The P3m1 space group was found to be typical for the compounds with low (x < 0.2) and high (x >= 0.75) Co concentrations, while the compounds with intermediate Co concentrations show different types of ordered structures. The lattice contraction with increasing x up to x = 0.5 is in good agreement with the electromotive force measurements in the Li|Li+|CoxTiS2 electrochemical cell. The magnetic properties of CoxTiS2 strongly depend on the Co content: the spin glass ordering at low (T < 50 K) temperatures, typical for x < 0.25, changes to the ferromagnetic one for 0.75 <= x <= 1.00, which is preserved even at high (T > 900 K) temperatures.

We present in this paper the experimental results of magnetothermal properties in Dy films and their comparison with the theoretical modeling of the same data. We consider the temperature interval between 80 and 200K, where Dy is ferromagnetic in low-temperature regions and helimagnetic for high temperatures. Our findings show that due to different phases in the considered temperature interval, the Dy induces thermal hysteresis in specific applied fields. We found that the ferromagnetic phase is favored in the heating process, and in the cooling process, the helimagnetic phase is favored.

Magnetic properties of amorphous Gd-Co ferrimagnetic films prepared by magnetron sputtering have been studied for various thicknesses. In a certain temperature range close to the magnetic compensation temperature, triple hysteresis loops and the characteristic features of the tempera-ture dependencies of magnetization were observed for all samples under consideration. Two-layer film model with an inhomogeneous chemical composition and a spin-flop transition scenario in two sub-lattice ferrimagnet was employed for understanding the origins of these phenomena. Within the framework of the spin-flop transition, the inter sub-lattice exchange coupling constant was estimated using various methods.

The mass magnetic susceptibility and resistivity of epitaxial films with different orientations of the c - axis of electron-doped Nd2-xCexCuO4+delta/SrTiO3 at different cerium concentrations and oxygen content were investigated. It was found the strong anisotropy of resistivity and the mass magnetic susceptibility at H = 100 Oe that is associated with the appearance of excess oxygen atoms between the conducting planes CuO2. An increase in the content of nonstoichiometric oxygen leads to an increase in the mass magnetic susceptibility and the destruction of the superconducting state.

Triple hysteresis loops were observed for amorphous ferrimagnetic Gd-Co films near the magnetic compensation temperature, which can be a consequence of both the spin-flop transition and the chemical composition gradient. In the work, an assessment of the possible chemical inhomogeneity of the films based on magnetic measurements was carried out and its relationship with the thickness of the samples was observed.

This paper presents a detailed study of the hysteresis properties of film structures based on bilayers of the Cr-Mn/Fe type. The temperature dependences of several parameters of the hysteresis loops of the Fe layers are determined for films varying in the composition and thickness of the Cr-Mn layer, as well as in the structure of buffer coatings. The compositional and temperature intervals of the existence of the antiferromagnetic ordering in the Cr-Mn layer and the related features of the temperature changes in the coercive force, its anisotropy in the plane of the films and the exchange bias field are established. The causal analysis of the established regularities is performed. Keywords: antiferromagnet, ferromagnet, bilayers, thickness, composition, temperature, texture, coercive force, exchange bias.

CoxTiS2 (x = 0.20, 0.30, 0.50, 0.75) compounds have a layered crystal structure with Ti atoms surrounded by the S octahedrons in the S-Ti-S layers and Co ions which could be surrounded both by the S octahedrons and tetrahedrons. The features of the crystal structure and magnetic properties of the polycrystalline CoxTiS2 samples were studied as a function of the cobalt concentration using X-ray diffraction and magnetization measurements. The disordered state of the Co atoms (x < 0.20) changes to the ordered one (x ≥ 0.20). The magnetic ordering arises at x = 0.20 with mostly antiferromagnetic interaction. For compound with x = 0.30 and 0.50 there is a weak ferromagnetic ordering. The ferromagnetic ordering is observed in Co0.75TiS2 below Tc = 375 K.

This paper presents a detailed study of the hysteresis properties of film structures based on bilayers of the (Cr-Mn)/Fe type. The temperature dependences of several parameters of the hysteresis loops of the Fe layers are determined for films varying in the composition and thickness of the Cr-Mn layer, as well as in the structure of buffer coatings. The compositional and temperature intervals of the existence of the antiferromagnetic ordering in the Cr-Mn layer and the related features of the temperature changes in the coercive force, its anisotropy in the plane of the films and the exchange bias field are established. The causal analysis of the established regularities is performed.

ZnCoO:H and ZnCoAlO:H films were synthesized by radio frequency magnetron sputtering in a (1 − x)Ar + xH2 mixed atmosphere with x = 0.2–0.5. The films contain different amounts of metallic Co particles (from 7.6% and higher) ~4–7 nm in size. The magnetic and magneto-optical (MO) behavior of the films was analyzed in combination with their structural data. The samples exhibit high values of magnetization (up to 377 emu/cm3) and MO response at room temperature. Two situations are considered: (1) the film magnetism is associated only with isolated metal particles and (2) magnetism is present both in the oxide matrix and in metal inclusions. It has been established that the formation mechanism of the magnetic structure of ZnO:Co2+ is due to the spin-polarized conduction electrons of metal particles and zinc vacancies. It was also found that in the presence of two magnetic components in the films, these components are exchange-coupled. In this case, the exchange coupling generates a high spin polarization of the films. The spin-dependent transport properties of the samples have been studied. A high value of the negative magnetoresistance of the films at room temperature (~4%) was found. This behavior was explained in terms of the giant magnetoresistance model. Thus, the ZnCoO:H and ZnCoAlO:H films with high spin polarization can be considered as sources of spin injection.

Triple hysteresis loops were observed for amorphous ferrimagnetic Gd-Co films near the magnetic compensation temperature, which can be a consequence of both the spin-flop transition and the chemical composition gradient. In the work, an assessment of the possible chemical inhomogeneity of the films based on magnetic measurements was carried out and its relationship with the thickness of the samples was observed. Keywords: amorphous magnetic films, perpendicular magnetic anisotropy, ferrimagnetism, magnetic domain structure, magnetic hysteresis.

Magnetization studies were carried out for Tb–Co thin films and Tb–Co/FeNi bilayers, prepared by magnetron sputtering technique. The composition of the Tb–Co films varied in the range of 19–24 at.%. All Tb–Co films were found to have perpendicular magnetic anisotropy in a wide temperature range. In addition, for some Tb–Co films, a spin reorientation transition was observed in the investigated temperature range. An analysis of the obtained results suggests that, in the course of deposition of the FeNi layer onto the Tb–Co layer, an interlayer magnetic boundary is formed, and its parameters depend on the composition of the Tb–Co layer. The magnetic structure peculiarities of this boundary determine the value of the exchange bias in Tb–Co/FeNi bilayers and its temperature dependence.

The structure, magnetic, and magnetoimpedance properties of Fe3Co67Cr3Si15B12 amorphous ribbons are studied using samples differing in the geometry, which are prepared by rapid quenching of the melt on a rotating wheel. The comparative analysis is performed for the as-quenched ribbons without additional treatments (A) and after relaxation annealing at 350°C (B) or thermomechanical treatment at 350°C under a specific load of 230 MPa (C). The selected treatments A and B correspond to the longitudinal magnetic anisotropy; in the case of annealed samples, the level of residual stresses is lower. Treatment C leads to the formation of transverse uniaxial magnetic anisotropy and record high sensitivity of giant magnetoimpedance effect (~200%/Oe) to the external magnetic field in the range of low fields ~2–3 Oe.

Hybrid metal-organic CH3NH3PbI3 perovskites are promising materials for photovoltaics and optoelectronics, and the recently discovered magnetic and electrical ordering in them stimulates their potential applications in spintronics. The temperature (in the range of 5–300 K) and magnetic field (up to 50 kOe) dependences of the magnetization of CH3NH3PbI3 single crystals for different directions of the magnetic field are measured. A strong anisotropy of the magnetic properties is found. If the magnetic field is perpendicular to the (001) crystallographic plane, the diamagnetic behavior of the magnetization is observed. If the field is oriented in the (001) plane, a transition from the ferromagnetic state to the paramagnetic state is revealed at a temperature of about 115 K. The features of the magnetic susceptibility observed in the low-temperature range are characteristic of the presence of antiferromagnetic correlations. In addition, in the CH3NH3PbI3 hybrid perovskite, a relation between the magnetic properties and the structural phase transition from the tetragonal to the orthorhombic phase is determined. The effective magnetic moment equals 0.76μB and 0.39μB in the tetragonal and orthorhombic phases, respectively.

The magnetic susceptibility in the high-quality epitaxial films Nd1.82Ce0.18CuO4/SrTiO3 with different orientation of the c-axis of electron-doped superconductors Nd1.82Ce0.18CuO4 was investigated. The strong anisotropic behavior of the magnetic susceptibility versus external magnetic field chi(parallel to)(H) and chi(perpendicular to)(H) at H<10 kOe and highly anisotropic temperature dependencies of the magnetic susceptibility chi(parallel to)(T) and chi(perpendicular to)(T) at low magnetic field H = 100 Oe is associated with different magnetic ordering of Nd3+ (Ce4+) rare earth magnetic ions and copper ions at different orientations of the external magnetic field with respect to the conducting planes of CuO2. The presence of the residual short ranged antiferromagnetic ordering of copper ions even in the overdoped region leads to magnetic anisotropy in the conducting planes.

The results of the study of the magnetic properties of exchange coupled Tb–Co/FeNi film structures obtained by magnetron sputtering in a wide range of temperatures are presented. It is shown that a decrease in the Zeeman energy upon approaching the compensation temperature of the ferrimagnetic layer is accompanied by a change in the sequence of magnetization reversal of the layers. The efficiency of the interlayer exchange coupling weakly changes with temperature.