Chemical structure and properties of disordered systems

1)。Mercury，a representative liquid metal，shows a metal-nonmetal transition in the supercritical region，and selenium，a representative liquid semiconductor，shows a transition from semiconductor to metal，and then to insulator。It is very important to investigate the relation between these physical properties and the atomic arrangement，density fluctuation or cluster formation in these materials。In the present study we have obtained some interesting results on the short-，medium-，and long-range structure of supercritical mercury and selenium，using the facilities of ESRF of Grenoble and Spring-8of Nishiharima as strong X-ray sources.2)。In superionic conductor glasses the dielectric relaxation associated with the glass transition cannot be observed due to large ionic conductivity。In the high frequency region，however，the contribution of ionic conduction is relatively small and it is expected to observe this dielectric relaxation。In this year，measurements of dielectric relaxat…More for AgI-Ag I D22 I D 2 O-B I D 22 ii D 2 O I D 23 D 2，AgI-AgPO I D 23 D 2 have been made at the Bourgogne University up to the glass transition temperature over the frequency range from 1 MHZ to 1 GHz。From the results obtained we discuss quantitatively considering the concentration fluctuation of oxides and halides in the glasses.We have also made some preliminary measurements on bromine NMR in an aqueous solution of ZnBr锡D22个D2 over a temperature range from room temperature to above100℃.3)。The alkali metal-mercury alloy systems show interesting electronic properties such as minimum of thermoelectric power.It is strongly suggested that the medium range chemical order due to the charge transfer between the constituent atoms is related to these properties。In this year we have measured the X-ray absorption(EXAFS And XANES)for the liquid Rb-Hg system，at ESRF of Grenoble。The absorption at the L-edge for Hg and at the K-edge for Rb was measured as a function of alloy composition。From these results we have found that the change of the stucture around the Hg and Rb atoms is strongly correlated with the electronic properties of this system。Less：Less

1). Mercury, a representative liquid metal, shows a metal-nonmetal transition in the supercritical region, and selenium, a representative liquid semiconductor, shows a transition from semiconductor to metal, and then to insulator. It is very important to investigate the relation between these physical properties and the atomic arrangement, density fluctuation or cluster formation in these materials. In the present study we have obtained some interesting results on the short-, medium-, and long-range structure of supercritical mercury and selenium, using the facilities of ESRF of Grenoble and Spring-8 of Nishiharima as strong X-ray sources.2). In superionic conductor glasses the dielectric relaxation associated with the glass transition cannot be observed due to large ionic conductivity. In the high frequency region, however, the contribution of ionic conduction is relatively small and it is expected to observe this dielectric relaxation. In this year, measurements of dielectric relaxat … More ion for AgI-AgィイD22ィエD2O-BィイD22ィエD2OィイD23ィエD2, AgI-AgPOィイD23ィエD2 have been made at the Bourgogne University up to the glass transition temperature over the frequency range from 1MHZ to 1GHz. From the results obtained we discuss quantitatively considering the concentration fluctuation of oxides and halides in the glasses. We have also made some preliminary measurements on bromine NMR in an aqueous solution of ZnBrィイD22ィエD2 over a temperature range from room temperature to above 100℃.3). The alkali metal-mercury alloy systems show interesting electronic properties such as minimum of thermoelectric power. It is strongly suggested that the medium range chemical order due to the charge transfer between the constituent atoms is related to these properties. In this year we have measured the X-ray absorption (EXAFS and XANES) for the liquid Rb-Hg system, at ESRF of Grenoble. The absorption at the L-edge for Hg and at the K-edge for Rb was measured as a function of alloy composition. From these results we have found that the change of the stucture around the Hg and Rb atoms is strongly correlated with the electronic properties of this system. Less