Obituary of Yurii Viktorovich Gorelkinskii

Professor Yurii Viktorovich Gorelkinskii, an experimental physicist widely known for his fundamental work in the field of electron paramagnetic resonance (EPR), died July 27, 2008 in Almaty, Kazakhstan.

Yurii was born in 1939. After graduation from the Department of Nuclear Physics at the Academy of Sciences of Kazakh SSR in 1965, he initiated his EPR studies at the Institute of Nuclear Physics, Academy of Sciences Kazakh SSR. In 1969, he completed his degree at the Ulyanov Electrotechnical Institute of Leningrad, and began his work at the High Energy Physics Institute, Academy of Sciences Kazakh SSR, where he served as the EPR group leader from 1970 until 1991. When the Institute of Physics and Technology, Almaty, was established in 1991, he continued his scientific career there until his death.

In 1971–72, Gorelkinskii developed the method of magneto-resonance EPR-tomography, which has found many applications in solid-state physics, chemical physics, and biophysics. In addition, throughout his career he made many contributions to the identification and property determination of important defects in semiconductors. Of particular importance in these studies was Yurii’s unique experimental contribution to the understanding of the “elusive” isolated self-interstitial in silicon and its interaction with other defects.

In 1986–7, Gorelkinskii discovered by EPR the hydrogen analogue of the anomalous state of muonium in crystalline silicon, where, in so doing, he determined the fundamental constants of atomic hydrogen in silicon (hyperfine structure, g-factor, kinetics for its reorientation, and the range of its stability). These results have proven to be essential in the development of defect models for hydrogen in semiconductors, and the direct and unambiguous determination of its diffusion kinetics in silicon. Gorelkinskii also made important contributions to the understanding of the electronic and molecular structure of bi-stable shallow donors induced by implantation of hydrogen into silicon, and he revealed and investigated the properties of ion-implanted helium, where he showed direct chemical bonding of the helium atoms to silicon neighbors in configurations stable at temperatures well above room temperature.

In 1995–99, Gorelkinskii identified oxygen-containing defects in silicon with bi-stable electronic and molecular structure, and followed that work with the discovery of hydrogen-accelerated low temperature migration of substitutional aluminum in silicon. He extended that work to the study of vacancy and interstitial clustering under proton implantation of silicon. The results of that work continue to be of interest from the point of view of the self-organized growth of nano-clusters and the use of these properties in semiconductor nanotechnology.

In addition to participation in many international conferences on ion implantation and defects in semiconductors, Yurii spent extended periods of time in both the Netherlands and the USA in collaborations with colleagues.

In 2001, he was awarded the Republic of Kazakhstan State Prize for Science and Technology for his work on “Ionic radiation modification of silicon properties”.

Yurii conducted active scientific work up until the end. He was a truly remarkable person, scientist, and colleague, and his bright creative life was interrupted suddenly without allowing him to carry out his many still active ideas. His colleagues, students, and friends deeply grieve over his premature demise. His continued contributions to the physics of defects in semiconductors will be strongly missed.