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Information × Registration Number 0214U005625, 0113U004207 , R & D reports Title Static and dynamic effects in magneto-ordered crystals and structures popup.stage_title Head Berzhansky Vladimir N., Registration Date 31-01-2014 Organization National Taurida V. Vernadsky University popup.description2 Research report: 96 p., 28 fig., 1 table, 90 refs. The object of research - phases, spin dynamics and magneto-optical properties of ferrіmagnets and antiferromagnets with different types of magnetic anisotropy. The goal of the work - development of the microscopic theory of static and dynamic effects in strongly anisotropic and isotropic non-Heisenberg magnets and the analysis of magnetic phases in nanoscale films and structures of iron garnets. Methods of research - diagram technique for Hubbard operators, magneto-optical spectroscopy methods. The theory of phase transitions and spin dynamics of isotropic non-Heisenberg one- and two-sublattice magnets are constructed using the diagram technique for Hubbard operators. Types of phase transitions depending on the material parameters of the system are defined on the basis of analysis of the magnon spectrum. The dynamic and thermodynamic properties of strongly anisotropic Ising antiferromagnets are investigated. It is founded that in addition to the expected ferromagnetic and quadrupole phases the another phase (supersolid phase) is realized. Within the framework of rotationally invariant theory the analysis of static and dynamic properties of strongly anisotropic easy-plane ferromagnets placed in an external magnetic field and having two possible orientations with respect to the easy plane. It is established that three phases can be realized: the ferromagnetic, quadrupole and quadrupole-ferromagnetic phases. It is founded that for nanoscale films synthesized on the treated by argon ions substrates, the inversion of signs of the magneto-optical effects that associated with the spin-reorientation phase transitions "order - order" occurs; at thicknesses less than 5 nm the phase transition of the "order- disorder" occurs. Magnetic phase diagram depending on the temperature, film thickness and composition is constructed. It is shown that a controlled inversion of the signs of magneto-optical effects can be realized by creating a double layer structure composed of films with different signs of magneto-optical effects. The possible mechanisms of the spin-reorientation phase transition in such hybrid nanostructures are proposed. Product Description popup.authors Гореліков Геннадій Андрійович Клевец Пилип Миколайович Космачов Олег Олександрович Ляшко Наталія Василівна Ляшко Сергій Дмитрович Михайлова Тетяна Владиславівна Попов В'ячеслав Валерійович Прокопов Анатолій Романович Фрідман Юрій Анатолійович Шапошніков Олександр Миколайович popup.nrat_date 2020-04-02 Close