No abstract

No abstract

No abstract

The ionic transport and the mechanical properties in solids are intimately related. However, few studies have been done to elucidate the background of that relation. With the objective to fill this gap and gain further understanding on the fundamental properties of ion conducting materials, we are studying systematically the mechanical properties of different materials. In the present study, after showing briefly our previous results obtained in crystalline materials, results regarding the relation between ionic conduction and mechanical properties in superionic glasses is presented. All these results indicate the intimate relation between the mechanical and ionic conduction. The results also indicate that the Grüneisen parameter and the Anderson–Grüneisen parameter of ionic conductors exhibit large temperature dependence and increase with temperature.

The aim of the present work is to understand the melting phenomena from a chemical bond point of view. We have studied the chemical trend of the melting temperature of AB type compounds by using the bond orbital model. It has been shown that the dominant interaction parameter determining the melting temperature depends on the types of materials. The peculiar behavior of Cu and Ag halides among the AB type compounds have been pointed out.KEYWORDS: melting, bond orbital model IntroductionMelting is one of the most popular physical phenomena. However, concerning the fundamental aspect of melting phenomena, many questions remains unsolved and not well understood. In order to understand the complicated mechanism of melting, many models have been proposed. For example, the famous empirical model proposed by Lindemann 1) states that a material melts when the amplitude of the thermal oscillation of the atoms becomes approximately 10% of the equilibrium interatomic separation. Most of the modern approaches to melting are based on lattice dynamical considerations.2) In the present report, the melting phenomena are investigated from a chemical bond point of view.3) We have studied the chemical trend of the melting temperature by using the bond orbital model. 4) By using this model, we can consider in a relatively simple way the essence of the nature of the chemical bond. In the past, this model has been used to study the structural stability of many AB type compounds such as NaCl and GaAs.