Structure
INSTITUTE OF METAL PHYSICS OF NASU.
Back

 
LABORATORY OF ELECTRON MICROSKOPY (43)

Laboratory of Electron Microscopy (43)

Laboratory of Electron Microscopy was founded in the Institute for Metal Physics of the Academy of Sciences of Ukraine in 1985 aiming on the development of basic research in the field of physics of strength and phase transformations in metallic systems, the development of new electron microscopic techniques and improving of their effectiveness. Since 2013 until 2015, the laboratory was in charge of Dr. V.L. Svechnikov. Since 2015 the laboratory is in charge of M.A. Skoryk.

The main research areas are:
- Atomic structure and thermodynamics of imperfections in high-alloyed steels and alloys; fine structure of planar defects and distribution of alloying elements on the imperfections of this type; stability of the crystal structure in the imperfect lattice and the nucleation of the martensite phase in the high-alloyed steels; 
- The fine structure of internal surfaces in metals and alloys and microsegregation on them; 
- Structure of the imperfections and distribution of alloying elements in steels and alloys after dynamic effects; 
- The electronic structure of imperfections and the binding energy of the light elements with the matrix and  precipitated phase in high-alloyed alloys. 

The laboratory also executes researches on planned subject areas of other divisions of the Institute in the field of amorphous materials, high-temperature superconducting ceramics, sputtered films, microelectronics, metal welding, explosive processing and other areas of modern science and science intensive technologies.

Improvement of electron microscopic techniques is conducted towards the development of an analytical (quantitative) electron microscopy, local elemental analysis, crystallographic analysis in micro areas, analysis of the energy spectrum of the passed through electrons and the local electronic structure of metallic systems. 

The laboratory also conducts collaborative research in the framework of international cooperation with scientific institutions in other countries (for example, Ruhr University, Bochum, Germany, etc.). Currently the electron microscopy laboratory meets the latest international standards as to its technical equipment and applied techniques. It is equipped with an analytical electron microscopy system of high resolution JEM-2000FXII produced by the company "JEOL" (Japan), equipped with an X-ray dispersive spectrometer AN10000/95S, LZ5 detector with UTW-window designed for the analysis of light elements from B (Z = 5) and spectrometer of electrons energy losses. 

This equipment allows to: 
- obtain an image of high resolution in the TEM mode (0.14 nm on imaging of a crystal lattice, 0.28 nm on points); 
- receive high-resolution images in the SEM mode (3 nm); 

- receive high-resolution images in the STEM mode (1.5 nm); 

- obtain images in back-reflected electrons in “TOPO” and “COMPO” modes; 

- conduct studies of the crystal structure of samples by electron diffraction methods: 

a) diffraction of high resolution, 

b) diffraction of high dispersion, 

c) diffraction from the selected point,

g) microdiffraction from small points of a sample (to 10 nm),

d) diffraction in a convergent beam,

e) the channeling pattern; 

- carry out elemental analysis of small point areas of the sample from B5 to U92 with an energy resolution of 143 eV and spatial resolution to 50 nm in the TEM mode and up to 10 nm in STEM-mode; 

- carry out spectroscopic analysis of the electrons according to the energies with an energy resolution of 2 eV at high spatial resolution. 

The laboratory is also equipped with modern equipment, allowing to produce thin samples for translucent electron microscopy, including a device for electrolytic thinning of metal samples "TENUPOL 3" company "STRUERS", an instrument for ion thinning of samples DUO ION MILL 600 companies "GATAN" (USA) and other subsidiary equipment. 

The laboratory has recently investigated the distribution of carbon on the imperfections in the structure of manganese austenite. It is shown that the concentration of this element in packing defects is much higher than in the matrix. The thermodynamic calculations of the energy of these imperfections taking into account the obtained direct experimental data on local concentrations of carbon indicate a good compliance of the calculated value of the defect energy of packing with experimental ones. Also, the distribution of manganese on imperfections was studied and its antisegregation properties in the presence of carbon were determined (Yu. N. Petrov, I.A. Yakubtsov).

The disintegration mechanism of the nitrous martensite by tempering of chromium steel was researched. It was found that in chromium martensite formation of nitride phases while tempering differs substantially from that in the Fe-N system. It was shown that in the initial stages of tempering the hexagonal iron hydride is formed, and at higher temperatures of tempering the redistribution of alloying elements and the formation of different nitride phases occurs. The fine structure of the imperfections in the alloyed austenite after dynamic (explosive, shock) loading was studied and significant differences in their fine structure and distribution of alloying elements in comparison with the static one were determined. The initial stages of crystallization in amorphous system Fe73,5 Si5 BNNb by heating were studied (Yu.N. Petrov, L.N. Trofimova).