Abstract :

The phenomena of magnetic and ferroelectric orderings have been generally regarded as “mutually exclusive” in oxide perovskites. The coexistence of the two phenomena with a coupling between the magnetic and ferroelectric order parameters in some magnetoelectric multiferroics has therefore evoked tremendous interest in recent years because of the interesting underlying physics and also the possibility of designing new generation sensor, actuator and memory devices. In this talk, I propose to present a broad introduction to the field of multiferroics followed by some of our recent results on the discovery of isostructural phase transitions in the solid solutions of BiFeO3, the only room temperature multiferroic with extremely high transition temperatures, that are responsible for two different exotic phenomena, namely the linear magnetoelectric coupling and existence of a critical point in a solid.

ABOUT THE SPEAKER:

Professor Dhananjai Pandey obtained his MSc and PhD degrees, both in Physics, in the years 1972 and 1976, respectively, from the Banaras Hindu University (BHU). His professional career started in 1977 with a Faculty position in the Department of Physics of BHU but he soon shifted to the Institute of Technology of BHU as a Faculty Member in the School of Materials Science and Technology in 1979. The Institute of Technology of BHU has recently become an autonomous Indian Institute of Technolgy (BHU) and Professor Pandey was the first Director of this new IIT. Presently, he is a Professor of Materials Science and Technology and J C Bose National Fellow at the IIT (BHU). He is internationally recognized for his contributions in materials physics and crystallography. A widely travelled scientist, he has delivered invited lectures/ plenary talks at numerous International and National Conferences in India and abroad. He has published over 200 research articles in journals of international repute, books and book-series. He is a Fellow of all the three premier science academies of India (Indian National Science Academy, Indian Academy of Sciences, National Academy of Sciences of India) and a Member of Asia Pacific Academy of Materials. He is a recipient of several awards/medals (INSA Young Scientist Medal, Materials Research Society of India Medal and its Annual Prize, Homi Bhabha Fellowship, DAE Raja Ramanna Award, Pt Jubilee Award of Indian Science Congress, Prof C N R Rao Education Foundation Award, J C Bose National Fellowship award etc). He has been the Co-editor of leading crystallography journals published by the International Union of Crystallography: Acta Crystallographica Section A and Journal of Applied Crystallography, and served on the Editorial boards of Phase Transitions, Materials Science forum and Bulletin of Materials Science. He is presently on the editorial advisory boards of Zeitscrift-fur-kristallographie, Bulletin of Materials Science, Pramana- a Physics Journal and J Applied Crystallography. He has served and continues to serve on many important national and international committees. He is presently the President of the Indian Crystallographic Association and Vice President of the Materials Research Society of India.