Chalcogenides ─ Metastability and Phase Change Phenomena

A state-of-the-art description of metastability observed in chalcogenide alloys is presented with the accent on the underlying physics. A comparison is made between sulphur(selenium)-based chalcogenide glasses, where numerous photo-induced phenomena take place entirely within the amorphous phase, and tellurides where a reversible crystal-to-amorphous phase-change transformation is a major effect. Applications of metastability in devices?optical memories and nonvolatile electronic phase-change random-access memories among others are discussed, including the latest trends. Background material essential for understanding current research in the field is also provided.

Dr A.V. Kolobov obtained his PhD and D.Sc degrees in 1984 and 1992 respectively from Ioffe Physico-Technical Institute (St. Petersburg, Russia) were he started his sceintific activities in the laboratory headed by Prof. B.T. Kolomiets, father of amorphous semiconductors. At various periods of time he was visiting researcher at Cambridge University (UK) on several fellowships including Kapitza Fellowship Award of the Royal Society, Ecole superieure de physique et de chimie industrielles de la ville de Paris (France), directeur de recherche at CNRS (France), Guest Professor at Katholieke Universiteit Leuven (Belgium). From 1994 he is senior scientist at National Institute of Advanced Industrial Science and Technology (Japan). Dr. A.V. Kolobov published over 160 papers in refereed journals and presented over 30 invited talks at international conferences. He is editor of ?Photo-induced metastability in amorphous semicondustors" (Wiley-VCH). In 2002 he received S.R. Ovshinsky Award for Excellence in amorphous chalcogenides.Dr A.V. Kolobov is member of editorial boards of Journal of Optoelectronics and Advanced Materials, Chalcogenide Letters, Journal of Ovonic Research.Professor Junji Tominaga received a Ph.D. in material science from Cranfield Institute of Technology (now, Cranfield University), United Kingdom in 1991. He was appointed as senior research staff at National Institute for Advanced Interdisciplinary Research of Ministry of Industrial Trading and Economy (MITI) Japan in 1997, after having worked as a research scientist in TDK R&D Center. In 2001, he became director of Laboratory for Advanced Optical Technology of National Institute of Advanced Industrial Science and Technology (AIST). Since 2003, he has been director of Center for Applied Near-Field Optics Research (CANFOR) of AIST. He has also been appointed professor of Tokyo Denki University since 2002, and visiting professor of Cranfield Univiersity since 2001. He is the inventor of super-resolution near-field structure (super-RENS) optical discs for ultrahigh density optical storage beyond the diffraction limit. For the invention and the related science and technological studies, he was awarded Minister Prize of MITI in 1999, and Japan IBM Science Award in 2000. Professor Tominaga is a co-author of two books: "Optical Nanotechnology -The Manipulation of Surface and Local Plasmons-," Springer-Verlag (2003), edited with Professor D. P. Tsai, and "Optical Near-Field Recording -Science and Technology-," Springer-Verlag (2005) written with Dr. T. Nakano, respectively. He published over 100 papers in refereed journals and also he has given more than 100 international presentations including 26 invited talks. He was a former associate editor of Japanese Journal of Applied Physics. Since 2003 he has been appointed to the technical program committee chairperson of International Symposium on Optical Memory (ISOM), and also appointed to many advisory committee members related to international & local optical data storage and near-field optics conferences. Professor Tominaga is a member of Optical Society of America, Institute of Physics UK, and Japanese Applied Physics Society. He is also a scientific advisor of Japan Science and Technology Agency (JST).