Viktor Grigoryevich Baryakhtar (born 9.08.1930) is a Soviet theoretical physicist and an academician of the Academy of Sciences of the Ukrainian SSR (1978). He was born in Mariupol (now Zhdanov). He graduated from Kharkov University (1953). In 1954—73 he worked at the Kharkov Physico-Technical Institute of the Academy of Sciences of the Ukrainian SSR; in 1973—82 he was head of a department and in 1975—78 deputy director of the Donetsk Physico-Technical Institute of the Academy of Sciences of the Ukrainian SSR, and from 1982 head of a department at the Institute of Theoretical Physics of the Academy of Sciences of the Ukrainian SSR.
His main research concerned magnetism, the physics of metals, plasma physics and superconductivity. Together with A. I. Akhiezer and S. V. Peletminsky he predicted magnetoacoustic resonance (1956). He developed the quantum theory of thermogalvanomagnetic phenomena in metals and semiconductors (1963—65). He constructed the theory of relaxation and high-frequency processes and of transport phenomena in ferromagnets (1959—62) and in antiferromagnets (1972—75). He was the first to study the interaction of magnons with dislocations in real crystals (1965). He proposed a new mechanism for relaxation processes in a plasma in a magnetic field (1964). He constructed the theory of the non-linear dependence of the temperature of the superconducting transition and of other thermodynamic characteristics of a superconductor on pressure and on the concentration of impurities (1964—70), and the theory of relaxation processes in superconductors. He carried out studies of the dynamics of cylindrical magnetic domains (1972—77). He predicted the formation of a domain structure in the neighbourhood of first-order phase transitions.
The State Prize of the Ukrainian SSR (1971). The K. D. Sinelnikov Prize (1978). Since 1982 he has been academician-secretary of the Division of Physics and Astronomy of the Academy of Sciences of the Ukrainian SSR.