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Information × Registration Number 0219U001456, 0114U006064 , R & D reports Title Spin states and quasiparticle excitations in complex systems with redused dimensionality popup.stage_title Head Pashkevich Yuriy Georgiyovych, Доктор фізико-математичних наук Registration Date 30-01-2019 Organization Donetsk Institute of Physics @ Engineering named after O.O.Galkin NAS of Ukraine popup.description2 The structural and magnetic phase transitions in self-doped lanthanum-samarium manganites were investigated using X-ray diffraction and magnetization measurements in the temperature range 4.2-300 K. The structural and magnetic phase diagrams were constructed. The combination of the observed phenomena indicates signs of the coexistence of a spin liquid, an electron-hole liquid and local superconductivity. In the system of gadolinium-strontium manganites, abrupt changes in the magnetization isotherms were observed at 4.2 K and in the interval of fields ± 7.5 T, which are characteristic signs of the existence of a gapless quantum spin liquid. For non-stoichiometric bismuth-containing rare-earth manganites, the optimum composition of the components is determined, at which the highest magnitude of magnetization and magnetoresistive effect is achieved. A new scheme has been developed for calculating the electronic levels and magnetic characteristics of transition and rare-earth metal ions in an arbitrary crystalline environment, which is based on a modified theory of the crystal field. The magnetic resonance spectra of impurity ions: copper in lithium galate and zinc tungsten spinel, and iron in the diluted magnetic semiconductor HgSe: Fe are studied. The magnetic anisotropy of rare-earth elements in iron-containing oxypnictides RFeAsO (R = Ce, Nd, Sm) is calculated. A cycle of studies of the spectra of electromagnetic waves of one-dimensional biperiodic photon and photon-magnon crystals, the results of which can be used in the development of optical filters with high selectivity, coatings and angle sensors, has been performed. The displacement of scattered light in the process of Brillouin scattering is considered for the first time. The features of reflection and transmission of a plane electromagnetic wave of a TM type, incident from the outside onto an anisotropic metamaterial layer with diagonal components of the dielectric constant tensor close to zero, are studied. The existence of maxima of transmission of electromagnetic TM-wave at special angles of incidence is confirmed. A series of studies of the influence of the magnetoelectric interaction on the spin-wave electrodynamics of magnetic materials has been performed. Using the example of a layer of an easy-axis antiferromagnet with an antisymmetry center, a previously unknown class of exchangeless spin waves with unusual dispersion properties was found. The possibility of controlling the type of spin waves in the ultrathin magnetic film of a ferromagnet using an external electric field, namely, switching between the direct and reverse types of spin waves, as well as the non-reciprocity of spin waves, is investigated. The fine structure of the magnetization of the Bloch-type skyrmion lattice was experimentally and theoretically investigated. A study of the four-nucler molecular magnet of D4h symmetry with locally anisotropic spin-spin exchange interactions was carried out. The evolution of the spectra of the complex depending on the parameters of the spin-spin interactions is considered. Product Description popup.authors Бабкін Роман Юрійович Буханько Артем Федорович Буханько Федір Миколайович Журавльов Олександр Вікторович Лєдєньов Микита Олексійович Ламонова Каріна Валентинівна Левченко Георгій Георгійович Любчанський Ігор Леонідович Пащенко Олексій Валентинович Савченко Андрій Сергійович Шевцова Тетяна Миколаївна popup.nrat_date 2020-04-02 Close