Pressure induced structural behaviour in f-electron based AB, AB(2) and AB(3) intermetallics

摘要

The rare-earth and actinide based compounds are endowed with several exotic physical and chemical properties due to the presence of f-electrons. Under pressure, the nature of f-electrons can be changed from localized to itinerant, leading to significant changes in their structural, physical and chemical properties. The present review on these f-electron based binary intermetallics compounds is an outcome of a detailed literature survey as well as our own research` during the last one decade. It attempts to bring out the structural sequences observed among the various homologues and their correlations with their electronic structure. It is seen that the majority of the AB type compounds show the NaCl to CsCl type structural transformation; whereas the AB(3) type compounds stabilizing in cubic structure at STP, remain stable over a wide pressure range. However, the AB(2) type compounds exhibit a variety of structural transitions, which broadly fall into the following sequence: MgCu2 ->(......)-> CeCu2 -> AlB2 -> ZrSi2 -> ThSi2 -> SmSb2 ->(..........) Further, the structural transitions, the transition pressures and bulk modulii values in any homologous series are seen to follow a systematic trend with respect to the atomic numbers of their constituent elements. (c) 2006 Springer Science + Business Media, Inc.