Department of Metal Electron Properties
Head of the Department: Vladimir M.Yurchenko,
doctor of physico-mathematical sciences
Directions of Scientific Researches: Kinetic, electron and magnetic properties, electrodynamics of conducting materials and superconductors; phase transitions; physics of strength and plasticity; theoretical analysis and experimental studies of structural and phase transformations in disordered metals and alloys.
Subjects of inquiry: physical systems (amorphous metallic glasses AMG, HTSC-ceramics, mono- and polycrystals, nano-systems with mesoscale inhomogeneities, synthesized high-molecular compounds and others) in a state far from a thermodynamic equilibrium.
There has been built up the theory of impurity segregation on phase and intercrystallite boundaries with regard to a lateral interaction and place control.
There have analytically described all stages (from a spinodal to a coalescence one) of the kinetics of structural transformations in glasses) including metallic ones).
Within the framework of the Ginzburg-Landau model there has been studied the evolution of antiphase domains at phase transitions of the first and second kinds of the order-disorder type.
For proper segneto-electrics there has been fixed that the formation of a poly-domain structure is more preferable than a direct transition to a mono-domain state of ordering.
On the base of our own experimental data there have been developed the following models: kinetics of non-isothermal crystallization of glasses controlled by diffusion both on a phase boundary (polymorphous and eutectic) and in the volume (primary); kinetics of a two-stage crystallization of AMGs; dependence of grain sizes in partially or completely crystallized glasses on annealing temperature and heating rate.
There have been detected non-monotonicities of the kinetics of pre-crystallization structural rearrangement of AMGs and compensational effects in the kinetics of structural relaxation and crystallization. A kinetic-thermodynamic interpretation has been considered.
There have been studies relaxation processes in the AMG samples under a permanently acting external deformation, under registration of responses to external impulse mechanical actions, in the free conditions. It has been experimentally found that under any conditions of testing the relaxation processes are contributed by the coherent mechanisms.
There were revealed the new phenomena: a gigantic magneto-striction (1996), a magnetic separation in textured YBaCuO-superconductors (1997), a galvanomagnetic effect in superconductors with an anisotropic pinning (1998).
There have been detected weakly damped oscillations of magnetic induction of a rigid superconductor with ω ~103Hz in a mixed state (the Shubnikov phase) of the Nb-Ti-plate.
There have been observed dynamic barriers at the inlet and outlet of magnetic flux in Nb when studying a superconductor screening properties and a flux capture.
There have been developed thermoelectric methods of measuring a melt layer temperature on the surface of a rotatable quenching roll, and determined empirical dependences between a cooling rate and a belt thickness according to the variations of external operation factors.
There have been synthesized a number of new AMGs of the system Fe-Co-P-B with a high level of magnetic-soft properties and higher thermal stability promising for manufacturing magnetic conductors and screens.
There has been developed a method of synthesizing massive samples of HTSC-oxides of the system Bi-Ca-Sr-Cu-O by the crystallization of amorphous phases obtained by a melt quick cooling.
The Institutes of the NAS of Ukraine: Donetsk National University (Donetsk), the Institute of Physics of Alloys (Donetsk), the Institute of Physics of Mining Processes (Donetsk), Dnepropetrovsk National University (Dnepropetrovsk), the Institute of the Materials Science Problems (Kiev), the Institute of Physics of Metals (Kiev), the Institute of Radio Electronics (Kharkov), the Institute of Solid-State Physics of the RAS (Chernogolovka, Russia), Kabardino-Balkarian University (Nalchik, Russia), the KTI (Stockholm, Sweden), the Institute of Physics (Warsaw, Poland), the Laboratory of Manufacturing and Studying Alloys (Nancy, France), research organization of Mexico, the projects and grants with the Republic of Uzbekistan, India, the USA, the Institute of Physics of Metals (Poznan, Poland).
1. E.P.Feldman, L.I.Stefanovich. Pisma v ZhETF 12 (63), 933 (1996).
2. E.Vigueras, E.Feldman, V.Yurchenko, L.Gumen, A.Krokhin. Phil. Mag. 3 (A81), 667 (2001).
3. A.V.Krajnikov, V.M.Yurchenko, E.P.Feldman, D.B.Williams. Surf. Sci. 1 (515), 36 (2002).
4. V.V.Chabanenko, A.I.D'yachenko, M.V.Zalutskii, V.F.Rusakov, H.Szymczak, S.Piechota, A.Nabialek. J. of App. Phys. 7324 (2000).
5. S.G.Rassolov, V.I.Tkatch, N.I.Selyakova. J. Appl. Phys. 10 (92), 6340 (2002).
6. V.I.Krysov. FMM 3 (93), 70 (2002).
7. V.S.Abramov, O.N.Beloshov. Materialovedenie 7, 9 (2001).