On 6 June, a seminar in memory of Doctor of Physics and Mathematics, Professor Nikolay Plakida (1937—2022) took place at the Laboratory of Theoretical Physics of the Joint Institute for Nuclear Research. The event was timed to coincide with the 87th anniversary of the birth of the Honorary JINR Employee and Honoured Scientist of the Russian Federation.

Chief Researcher of the Scientific and Experimental Department of Neutron Studies of Condensed Matter at the Laboratory of Neutron Physics at JINR (FLNP JINR) Victor Aksenov opened the seminar. He outlined the main periods of the outstanding researcher’s scientific biography: from his student years to the last years of his life. One of the most significant achievements in the career of Nikolay Plakida was the development of the theory of strongly anharmonic crystals. Moreover, he proposed the internationally recognised microscopic theory of high-temperature superconductivity (HTSC). His fundamental monograph entitled “High-temperature cuprate superconductors” (Springer, 2010) is a reference book for modern researchers. In addition, in the late 1960s, as a theorist, he actively participated in the development of the scientific programme of the IBR-2 Reactor.

“I have never met such a person as Nikolay Plakida. He had an extraordinary trait that set him apart: he was always eager to talk about things he knew. One’s desire to share knowledge is the quality of a truly great scientist and teacher, whose lasting impact will remain in the hearts and minds of everyone who knew him,” Victor Aksenov recalls.

A leading researcher at the BLTP JINR Solid State Theory Sector Victor Yushankhai spoke about his memories and the experience of many years of joint work with Nikolay Plakida. It was under the leadership of Nikolai Plakida that Victor Yushanhkai began to study HTS. In his speech, he described in detail how research into high-temperature superconductors has developed.

In the second part of the seminar, FNLP JINR Chief Researcher Anatoly Balagurov presented a talk “Crystals, alloys, and neutron diffraction: the cooperation of theorists and experimentalists”. Head of the Department of Electrochemistry of the Faculty of Chemistry of Moscow State University Evgeny Antipov spoke about the problems and prospects of metal-ion batteries. At the end of the event, Head of the Laboratory of Quantum Mechanical Systems of the Institute of Mathematical Problems of Biology of the Russian Academy of Sciences Victor Lakhno spoke about the role of Nikolay Plakida in the development of polaron theory.

The seminar dedicated to Nikolay Plakida was a special, truly important event for the Institute, honouring the memory of the outstanding scientist. At the same time, the event establishes a connection between past, present, and future of science, passing on the valuable experience and legacy of Nikolay Plakida to the younger generation of scientists.