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Information × Registration Number 0211U005704, 0111U007231 , 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 22-12-2011 Organization Institute of physics NASU popup.description2 It is established, that the growth-induced anisotropy of granules with approximately similar orientation of the easy axes of granules perpendicularly to a film plane manages to be fixed only at the nano-composite of Co in Al2On matrix , with n close to 3 between the investigated nano-composites of the Сo and CoNbTa in Al2O3, CaF2, SiO2 and MgO matrixes. A distinction of the low-temperature manifestation of the positive low-field magnetoresistance in the Co/Al2O3 films received by different technologies is established. Comparative magneto-static measurements for the films with Co granules in Al2On matrixes grown in the Ar atmosphere with addition of oxygen and without it are carried out. Theoretical consideration and a computer modeling of systems with perpendicular anisotropy in a magnetic field inclined to an axis of anisotropy of granules and systems of granules with a casual inclination of an axis of anisotropy concerning a dominating perpendicular direction is executed. The mechanisms of an equilibrium magnetization of nano-granular film Co-Al2O3 (61 at. % Co) with perpendicular anisotropy of the single-domain granules are investigated. It is shown, that a film magnetization is changed critically in the process of transition from a state with non-uniform orientation of the granules magnetic moments to a state with their identical direction, induced by the inclined magnetic field, in spite of the fact that in the inclined field the a vector of an external magnetic field, field of demagnetizing and the magnetic moments of granules have different directions. It is proved, that such criticality is consequence of indemnification of a transversal component of an external magnetic field by a demagnetizing field. The influence of a process of slope of the magnetic moment of granules and of a process of their turning over on the curves of magnetization is determined. It is shown, that in a non-uniform state the magnetostatic energy of granular film with the elongated form of particles can be described by the sum quasi-single-granular contribution and a collective quasi-film one. Results of consideration of equilibrium magnetization in two-level model of orientations of the magnetic moments of particles are well correspond to the data investigated nano-granular film Co - Al2O3 with 61 ат. % Co. Product Description popup.authors Бондар Олександр Васильович Калита Віктор Михайлович Лозенко Альберт Федорович Рябченко Сергій Михайлович popup.nrat_date 2020-04-02 Close