National Academy of Sciences of Belarus

OLEKHNOVICH Nikolai Mikhailovich

OLEKHNOVICH Nikolai Mikhailovich

Nikolai Mikhailovich Olekhnovich (b. 02.05.1935, v. Voronichi, Slonim district, Grodno region), physicist. Academician of the National Academy of Sciences of Belarus (1996; corresponding member since 1989), Doctor of Physico-Mathematical Sciences (1988), Professor (1991). Honored Scientist of the Republic of Belarus (1999).

Scientific research are devoted to the problems of chemical bonding in solids, X-ray diffraction in real crystals, the production of new materials, including using high pressures. He developed methods for the experimental determination of the spatial distribution of the electron charge and potential in crystals and the determination of their physical properties, and revealed the covalent-ionic nature of the chemical bond in an important group of semiconductor crystals. Developed x-ray diffraction-polarization analysis of real crystals. He discovered and investigated the phenomena of birefringence and depolarization of x-rays during diffraction in dislocation crystals, on the basis of which he developed the polarimetry of the x-ray frequency range. He proposed methods for monochromatization of X-ray synchrotron measurement with polarization conversion. Based on the effects of dynamic X-ray scattering for distorted single crystals with a statistical distribution of defects, developed methods for identifying the type of defects, estimating their parameters, and also methods for precision determination of structural factors and characteristics of the dynamics of the crystal lattice. He constructed state diagrams for oxide systems, obtained and investigated a number of new metastable perovskite phases of ferroelectrics. Developed an approach for describing phase transitions in crystals of halide and oxide compounds with a perovskite-type structure based on taking into account the strength of interatomic bonds and the multiwell potential due to it.

Author of over 300 publications, incl. 14 inventions.

Awarded with a medal.

Major papers:

  1. Интегральные характеристики дифракции рентгеновских лучей в монокристаллах с хаотическим распределением дислокаций // Металлофизика. 1986. Т.8, №1.
  2. Dynamical effects of X-ray scattering in Laue geometry for Si crystals with structure defects (совм. с А.Л. Карпеем) // Phys. Stat. Sol. (a). 1984. Vol. 82, No.1.
  3. Birefringence and depolarition effects of X-ray scattering in Laue geometry for highly distorted crystals (совм. с А.В. Пушкаревым) // Там же. 1990. Vol. 119, No.1.
  4. Длины ненапряженных связей и соответствующие им радиусы катионов в кристаллах со структурой типа перовскита // Кристаллография. 2004. Т.49, №5.
  5. Напряженность межатомных связей и многоямный потенциал в кристаллах со структурой типа перовскита // Кристаллография. 2005. Т.50, №3.
  6. Relationship between the rotation angles of octahedra and bond-strength energy in crystals with perovskite structure // Crystallography Reports. 2007. Vol.52. No.5.