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In this work, the directed crystallization of glass-coated magnetic microwires of Co-rich composition is realized with the aim to develop a novel technique for micro-magnet fabrication. The onset of the process is caused by local overheating above the primary crystallization temperature while the rest of the wire sample is at the temperature slightly below the crystallization temperature. This creates the conditions for spontaneous formation of microcrystallites at the wire edge and the movement of the crystal-amorphous interface along the wire. It was found that the directed crystallization is possible in a narrow temperature interval of 5-78 near the crystallization temperature. The effect of the directed crystallization on the magnetic properties is evident from a giant increase in coercivity, up to 1000 times. The directed crystallization was also assisted by application of a magnetic field which resulted in greater increase in coercivity, up to 1500 times and the coercivity value reached 69400 A m À1 . For comparison, at a standard crystallization the coercivity increases by 8-10 times being in the range of 2000-4000 A m À1 . The developed micro-magnets can find a range of applications in miniature sensors, actuators, and manipulators.

The method of modernized ion-plasma sputtering produced metastable states, including nanocrystalline and amorphous phases in films of Fe-Ag, Fe-Bi, Fe-Ag-Bi, Fe-Co-Ag and Ni-Ag alloys whose components do not mixed in the liquid state. The periods of the crystal lattices and the dimensions of the crystallites of the nonequilibrium phases in the fresh-sputtered state and after the heating are determined. The temperatures of the beginning and the end of the decomposition of metastable phases are established when heated at a constant rate. The electric and hysteretic magnetic properties of films in freshly dusted and thermally processed states are measured. The compositions and conditions for obtaining films with low values of the temperature coefficient of electrical resistivity (~ 10-5 K-1) and high coercive force (HC ~ 150 kA/m) are established. Such films can be promising for use as thin-film precision resistors and magnetic information carriers with an increased recording density.

The quantitative estimation of maximum level of cooling rates in the process of casting microwires in glass insulation is given. The shown possibility of nonequilibrium formation of microwire substance is due to the influence of an amorphous substrate in the form of glass insulation. The amorphous state in the case of thin microwires with cast iron vein Fe‒20 at.% C confirms the implementation of an increased (compared to splat-quenching) level of nonequilibrium formation of microwires in combination with updated rates of cooling and increased degree of supercooling of liquid microwire vein.

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The article investigates the structure and physical properties of the multicomponent high-entropy alloy CoCr0.8Cu0.64FeNi in the cast and quenched state. The composition of the alloy under study is analyzed using the criteria available in the literature for predicting the phase composition of high-entropy alloys. These parameters are based on calculations of the entropy and enthalpy of mixing and also include the concentration of valence electrons, the thermodynamic parameter Ω, which takes into account the melting point, entropy of mixing, and enthalpy of mixing. Another important parameter is the difference in atomic radii between the alloy components δ. Cast samples of the CoCr0.8Cu0.64FeNi alloy of nominal composition were prepared on a Tamman high-temperature electric furnace in an argon flow using a copper mold. The weight loss during the manufacture of ingots did not exceed 1%, and the average cooling rate was ~ 102K/s. Thereafter, the cast ingot was remelted, and films were obtained from the melt. The splat quenching technique used in this work consisted of the rapid cooling of melt droplets when they collide with the inner surface of a rapidly rotating (~ 8000 rpm) hollow copper cylinder. The cooling rate, estimated from the film thickness, was ~ 106 K / s. X-ray structural analysis was performed on a DRON-2.0 diffractometer with monochromatic Cu Kα radiation. Diffraction patterns were processed using the QualX2 program. The magnetic properties of the samples were measured using a vibrating sample magnetometer at room temperature. The microhardness was measured on a PMT-3 device at a load of 50 g. In accordance with theoretical predictions confirmed by the results of X-ray diffraction studies, the structure of the alloy, both in the cast and in the quenched state, is a simple solid solution of the FCC type. The lattice parameters in the cast and liquid-quenched states are 0.3593 nm and 0.3589 nm, respectively. Measurements of the magnetic properties showed that the CoCr0.8Cu0.64FeNi alloy can be classified as soft magnetic materials. In this case, quenching from a liquid state increases the coercivity. On quenched samples, increased microhardness values were also obtained. This can be explained by internal stresses arising during hardening.

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