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Information × Registration Number 0223U000894, 0121U112687 , R & D reports Title Fulfillment of tasks of the perspective plan of development of a scientific direction "Mathematical sciences and natural sciences" Sumy State University popup.stage_title Head Pohrebniak Oleksandr D., д.ф.-м.н.Protsenko Ivan Yu., Доктор фізико-математичних наук Registration Date 21-01-2023 Organization Sumy State University popup.description2  The electrophysical and magnetoresistive properties (specific resistance, thermal resistance coefficient, strain sensitivity and magnetoresistance with giant signs), electronic properties (surface and Fermi energy mean free path length of electrons), and some dynamic ones (Debye temperature, lattice parameter) and thermodynamic characteristics were studies carried during the first part in 2022. The research was conducted at the phenomenological level within the framework of the concept of additivity of physical quantities in accordance with the concentration of individual elements. The methodology can be divided into several stages: a) the four or five-component high-entropy film alloys (HEA) were considered; b) a phase-forming equiatomic combination of three or four elements was set, c) the concentration of the fifth element changed from 0 to 30 at.%. The selection of elements (Fe, Ni, Co, Cu, Al, Cr) made it possible to guarantee the formation of solid solutions without magnetic quasigranules or without crystallites of magnetic intermetallics. The calculated results and the experimental ones agreed very well. For the first time, a new feature of the strain-resistive effect in HEA films was observed, namely, the value of the strain-sensitivity coefficient, it turns out, is limited by narrow intervals of the Grüneisen parameter and Poisson's ratio, that's why cannot expect a value of the strain-sensitivity coefficient greater than 5 units. When performing the second task, significantly new results were obtained: within the framework of the rigid dipole model, a generalized system of differential equations for the magnetization angle, which describes the rotational motion of a nanoparticle in a viscous liquid, and the coordinates of the center of the nanoparticle, which describes its translational motion, under the action of a variable gradient and constant uniform magnetic fields. Product Description popup.authors Denisov Stanislav I. Lysenko Oleksandr V. Lyutyy Taras V. Odnodvorets Larisa V. Pasko Olha O. Pylypenko Oleksandr V. Protsenko Ivan Yu. Shabelnyk Yurii M. Shpetnyy Ihor Oleksandrovych Shumakova Nataliya I. popup.nrat_date 2023-01-21 Close