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Information × Registration Number 0218U000496, 0117U006438 , R & D reports Title The development of ferromagnetic films and the creation on their basis of magnetically controlled composite microwave structures popup.stage_title Head Solovyov Kateryna Dmitrievna, Registration Date 31-01-2018 Organization V.I.Vernadskii Institute of General and Inorganic Chemistry NASU popup.description2 A technology has been developed for the synthesis of nanoscale particles of ferromagnetic materials by sequential precipitation of hydroxides at controlled pH values. It is shown that the formation of the crystal structure of particles is observed after heat treatment at 500 ° C. It is established that after heat treatment at 700 ° C, the particles are nanoscale and their size varies within the range of 15-35 nm and they can be used to film films when compositing structures are created. The resulting film-forming suspensions with different concentrations (175 g / l, 350 g / l and 525 g / l) for the synthesis of thick nanocrystalline nickel ferrite films with a spinel structure. The method of screen printing produced thick films on the surface of a dielectric resonator а-Al2O3 with thicknesses of 50, 70, 100 and 200 ?m. It is shown that the microstructure of nickel ferrite films is characterized by the plate form of particles with an average diameter dsp. = 85 nm. The possibility of magnetic control of the parameters of composite structures "dielectric resonator а-Al2O3 - ferrite film" is investigated. It is established that the magnetic field has a significant effect on the resonant frequency and a significant effect on the quality factor and the transmission coefficient of the structure. It is shown that the largest controllable magnetic field changes in the transmission coefficient and the shift of the resonant frequency were characteristic for a film with a thickness of 100 mkm and amounted to 56.4 dB and 26 MHz, respectively. A technology for manufacturing composite resonators of the microwave range based on a dielectric resonator (barium tetrutitanate doped with zinc) and nickel ferrite with a spinel structure has been developed. It is shown that such structures are characterized by a relatively high Q-factor (up to 5000 in a magnetic field) and allow changing the resonant frequency by an external magnetic field. The range of resonance frequency is 29 MHz at a resonance frequency of 11.613 GHz. The developed composite resonance elements are characterized by considerable nonreciprocity, which is important when creating a number of microwave devices (in particular, gates). The difference in the level of energy absorption, depending on the direction of the electromagnetic wave, is up to 40 dB. Product Description popup.authors Солопан С.О. Федорчук О.П. Шлапа Ю.Ю. popup.nrat_date 2020-04-02 Close