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Information × Registration Number 0212U005797, 0112U004574 , R & D reports Title Magnetic and magneto-transport properties of the thin-film nanogranular composites with growing-caused anisotropy. popup.stage_title Head Ryabchenko Sergiy Mykhajlovych, Registration Date 28-12-2012 Organization Institute of physics NASU popup.description2 Magnetic and magnetotransport properties of the nano-granular films of "the ferromagnetic metal granules - a dielectric matrix" type with anisotropic granules were studied. The growth-induced anisotropy of granules with perpendicular orientation of their easy axes with respect to film plane was revealed at the Co in matrix of Al2On composites. It was established, that in the films, grown in Ar atmosphere with the O2 addition, an axis of the granules anisotropy have a certain random inclination with respect to the normal to film. Mechanisms of magnetization of the Co-Al2O3 (61 at.% Co) film were investigated in inclined field. Theoretical consideration and computer simulation of systems with perpendicular anisotropy in inclined magnetic field have been carried out. The description of the equilibrium magnetization in two-level model of orientations of the magnetic moments of particles is well agreed with the experimental data for the above film. The model of low-field positive magnetoresistance as a consequence of magnetization of the films with perpendicular anisotropy perpendicularly to the easy axis of magnetization under presence of intergranular ferromagnetic interaction has been developed. The Co0.55-(Al2O3)0.45 film that grown with addition of O2 to Ar was studied by the magnetometry, FMR and magnetic force microscopy (MFM). Presence of a superferromagnetic state with a long-range order, caused by interpartial interaction was revealed. The dipole-dipole and ferromagnetic exchange interactions competition leads to occurrence of non-uniform labyrinthine strip domain structure with the domains width much greater than granules size. The temperature changes of magnetization in strip domains were measured by a control of a contrast of MFM image. The mean field model, which was developed earlier for the superferromagnetic state coercivity, was compared to the results of measurements on the basis of the MFM contrast. It has been found the adequacy of this model. Product Description popup.authors Бондар Олександр Васильович Калита Віктор Михайлович Кулик Микола Миколайович Лозенко Альберт Федорович Рябченко Сергій Михайлович Тимофієв Андрій Олександрович popup.nrat_date 2020-04-02 Close