Download or read book Fundamental Investigations on Open-framework Intermetallic Materials of Group 14 written by Matthew K. Beekman and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Crystalline open-framework intermetallics have long attracted the attention of chemists, physicists, and materials scientists. The intriguing structures such materials exhibit are often intimately related to the unique physical properties they possess. The present work is focused on the preparation and characterization of open-framework intermetallic materials based on group 14 elements, in particular those crystallizing in clathrate and related structures such as the clathrate-II phases. Materials possessing the clathrate-II crystal structure have received increased attention in recent years, as a result of both the unique properties they exhibit as well as potential for use in technologically important applications such as thermoelectrics, photovoltaics, and optoelectronics. However, in comparison with other clathrate structure types, characterization of clathrate-II materials has in general been far less extensive. Moreover, many conceivable compositions have yet to be realized. The purpose of this work is to expand the current knowledge of the structural, chemical, and physical properties of these materials, while simultaneously exploring new compositions and synthetic routes to clathrate-II phases. One of the unique and promising aspects of clathrate-II materials is the ability to vary the guest concentration, which is shown to have significant implications for the structural and physical properties of NaxSi136 (0