Papers by Author: G.S. Patrin

Abstract: We demonstrate that a magnetic tunnel structure irradiated by microwaves can generate a significant voltage signal due to the rectification effect. The measurements were carried out using current-in-plane geometry with a current flowing parallel to the interfaces in the structure. A value of the microwave-induced voltage strongly depends on a bias current and can be driven by a magnetic field. The rectification effect is discussed both in classical terms of nonlinearity of the current-voltage characteristic and using a mechanism that involves the interplay between the spin-polarized current and magnetization dynamics in the magnetic tunnel structure.

Abstract: Co-Ti-O nanogranular films with different volume concentrations of a magnetic phase and Co/Ti-O layered structures with different numbers of layer pairs are studied by the magneto-optical Kerr effect. It is shown that, unlike the case of homogeneous metal films, the magneto-optical spectra of the nanogranular films exhibit resonance with a significant increase in the Kerr rotation angle in the wavelength range 500-700 nm. It is found that the Kerr rotation angle of the Co/Ti-O layer structures in the wavelength range 500-600 nm grows by an order of magnitude as compared to its value for ordinary Co films.

Abstract: Exchange bias and coercivity of the hysteresis loop of a low-coercive layer in magnetic three-layered structure prepared by chemical deposition are studied. It is established that the coercive force in the films obtained nonmonotonically changed with the low-coercive layer thickness. The specificity of magnetization reversal of exchange-biased layers is analyzed.

Abstract: Interlayer interactions in FeNi/Bi/FeNi trilayers have been experimentally studied. Based on the data of SQUID magnetometry and magnetic resonance investigations, it is shown that the interlayer interaction is determined by a bismuth spacer thickness and temperature. The giant magnetoresistive effect in the trilayer films has been discovered.

Abstract: The results of experimental investigations of Fe1-xCoxSi crystals in the impurity limit are presented in this article. We made an attempt to study changes of magnetic properties and conductivity in mixed Fe1-xCoxSi crystals in the impurity limit. Magnetoresistance properties are well described in the framework of Kondo model. The presence of Co-subsystem leads to the occurrence of spin-dependent channel in electron scattering conduction.

Abstract: The interlayer coupling in Co/Ge/Co trilayer films has been experimentally studied by the SQUID magnetometry and electron magnetic resonance. It has been found that the interlayer coupling is temperature-dependent. The values of the exchange constants have been determined.

Abstract: The surface morphology and magnetic properties of layered Ni-Ge films were investigated. The films surface has been shown to consist of the grains of 2 - 4 nm in height with the average radius of about 40-80 nm. Magnetization temperature dependences are different for FC and ZFC processes; in the latter case, the magnetization maximum is observed near the temperature Tm~50K. The exchange bias effect is observed at low temperatures. The results are explained by the formation of the antiferromagnetic phase in the interface between Ni and Ge layers due to the Ge and Ni mutual diffusion.

Abstract: The results of experimental research into magnetic properties of amorphous Co-P films obtained by chemical sedimentation on various intermediate layers have been represented. The nuclear magnetic resonance (NMR) spectra of films sedimentated on intermediate layers of Pd crystal and amorphous NiP compound have been measured .The features of formation of domain structures and magnetization processes in the presence and absence of the induced anisotropy have been described.

Abstract: Photo-induced self-oscillations of stripe structures are studied in FeBO3 crystals at low temperatures. Experimental data show that the observed oscillations have a relaxational character. On the basis of the research carried out, a model for such oscillations is presented.

Abstract: Data on the magnetic properties of polycrystalline Pr0.7Ca0.3MnO3 manganite films obtained for the first time by extraction pyrolysis are presented. The effect of synthesis temperature on the magnetic properties of the manganite films is shown.