“Scientific Regiment”: Yevgeny Zavoisky discovers electron paramagnetic resonance
In the run-up to the Victory Day (9 May), Kazan Federal University joins the Scientific Regiment initiative and speaks about its employees’ endeavors during the Great Patriotic War of 1941 – 1945.
Yevgeny Zavoisky’s name left a major mark in the history of physics thanks to his discovery of electron paramagnetic resonance (EPR) and his research in nuclear physics, controlled thermonuclear fusion, and physical electronics.
Electron paramagnetic resonance laid the foundation for radio spectroscopy and influenced many scientific disciplines.
In 1933 – 1947, Yevgeny Zavoisky served as Chair of the Department of Experimental Physics of Kazan State University. In 1941, the Department started its inquiries in paramagnetic relaxation.
The prehistory of EPR started in 1895 when Pierre Curie first quantified the magnetic behavior of matter. Works by Otto Stern, Walther Gerlach, Samuel Goudsmit, George Eugene Uhlenbeck, and others then followed.
While studying paramagnetic relaxation in condensed matter in the early 1940s using the method of resonant absorption of radio waves with a frequency of 100 MHz and the method of modulating a constant magnetic field, Zavoisky managed to observe the absorption peaks of a microwave field in anhydrous chromium chloride, in manganese and copper sulfates, and in other paramagnetic salts. In these works, in particular, a linear dependence of the strength of a constant magnetic field on the frequency of an oscillating microwave field was shown, as well as an inverse dependence of the paramagnetic susceptibility (magnitude of the effect) on temperature.
Zavoisky first observed a magnetic resonance signal on his oscillograph on 21 January 1944. The phenomenon of EPR was registered in the Soviet Union’s State Register of Scientific Discoveries on 23 June 1970 with official priority from 12 July 1944.
One of the most important events in physics of the 20th century led to great successes in the physics of magnetic phenomena, solid state physics, physics of liquids, inorganic chemistry, mineralogy, biology, medicine, and other sciences. Based on the phenomenon of resonant absorption of microwave radiation, for example, a quantum paramagnetic amplifier has been created, which is used to implement deep space communications.
During the war, Zavoisky worked with other employees in wood felling and unloading works on the Volga River. The firewood was used for heating at the University and other facilities. When the University received its own agricultural land near Kazan, Zavoisky partook in harvest labor in summer months, including engine repairs.
As most of the other locals in the war years, the scientist also dug trenches and practiced shooting, joined patrol squads and a fire team.
Notes
Yevgeny Zavoisky (1907 – 1976) – Soviet physicist, alumnus of Kazan University (1931), Candidate of Sciences in Physics and Mathematics (1933), and Doctor of Sciences in Physics and Mathematics (1945). He was thrice awarded the Order of Lenin and once the Order of the Red Banner of Labor. He received the 3rd Degree Stalin Prize (1949), the Lenin Prize (1957), the Order of the Hero of the Socialist Labor, and was nominated for the Nobel Prize six times from 1957 to 1976. He took part in nuclear weapons research in the 1940s.
Zavoisky is memorialized in various capacities. The city of Kazan has a street under his name. Kazan Physical-Technical Institute was named after Zavoisky in 1984. The Museum of Zavoisky was opened in Kazan University in 1997. His bust was placed in front of the Institute of Physics of KFU in 2004.
Zavoisky International Prize has been awarded since 1991 for contributions to electron paramagnetic resonance.