Electrcal Properties of liquids and glasses composed of chemically different substances

本课题的研究成果总结如下：1.研究结果表明：金属-非金属体系：我们研究了cs -氨-甲胺体系的电导率和Cs-133核磁共振，并将所观察到的浓度波动与体系的金属-非金属（MNM）跃迁联系起来。对na -氨体系进行了200 MHz的低场EPR测量，以显示在整体MNM转变之前的局部金属化。研究了银和铋纳米粒子在硼酸盐玻璃中的析出，发现了它们的物理性质（等离子体激元吸收或熔化温度）与尺寸的关系。Tl-Ge-Te体系中的NM跃迁与EMF测量所得的热力学性质有关。有机-无机混合超离子导体：研究了AgI-四烷基碘化铵混合玻璃的电导率随AgI体积分数的变化规律，表明AgI从超离子状态渗透到绝缘体状态。并用核磁共振、EXAFS、中子和x射线小角散射进行了显微观察。离子盐-分子液体体系：随着盐浓度的增加，lino_3 -甘油体系的粘度增加，而电导率降低。对氯化锂-水系统也进行了类似的测量。提出了由溶剂化锂离子和溶剂分子组成的网络结构。从这些结果可以得出结论，在由化学性质不同的物质组成的液体和玻璃中，由于相分离或络合物形成而引起的局部均匀性决定了体系统的电学性质。

The results of the present project are summarized as follows :1.Metal-nonmetal systems : We have studied the electric conductivity and Cs-133 NMR in the Cs-ammonia-methylamine system and correlated the observed concentration flucutuation and the metal-nonmetal (MNM) transition of the system. Low field EPR measuremts at 200 MHz were carried out for the Na-ammonia system to show the local metallization prior to the bulk MNM transition. Precipitation of Ag and Bi nano-particles in borate glasses was investigated and the size dependence has been found for their physical properties such as plasmon absorption or melting temperature. The NM transition in the Tl-Ge-Te system has been correlated to the thermodynamic properties obtained from EMF measuremnts.2.Organic-inorganic mixed superionic conductors : The electrical conductivity of AgI-tetraalkylammonium iodide mixed glasses has been studied as a function of volume fraction of AgI,which shows a percolation transition from the superionic to insulator states. Microscopic investigations were also made with NMR,EXAFS,neutron and X-ray small angle scattering.3.Ionic salt-molecular liquid systems : The viscosity of the LiNO_3-glycerol system increases with salt concentration, while the electrical conductivity decreases. Similar measurements have been made for the LiCl-water system. Network structures composed of solvated lithium ions and solventmolecules have been suggtested.From these results it is concluded that in liquids and glasses composed of chemically different substances the local in homogeneities due to phase separation or complex formation determine electrical properities of the bulk systems.