An attempt has been made in this review to cover recent information on the structure of supersonic conductors investigated by the diffuse scattering measurement. The presence of low-energy excitations in crystalline superionic conductors and the superionic conducting glass is investigated by neutron inelastic scattering measurements. The relation between the excitation energy and the mass of the cations is discussed.
In phyllosilicate minerals, specially in fine-grained clay minerals, it is well known that interstratification is formed among two or more kinds of clay minerals being elementary component layers. The interstratification can be described by using the statistical theory and analysed with the XPD theory concerning one-dimensionally disordered crystals. Recently, the interpretation of the interstratified structure of clay minerals has attracted special interest in crystallographical and geochemical fields. This text gives an interpretation to the Interstratified structure and points at geochemical interest focusing to the crystallochemical problem of interstratified clay minerals.
Topological characteristics of zeolite frameworks has been reviewed on the basis of concentric cluster (CCL) and Hamiltonian graph representations. The framework characteristics has been confirmed to be faithfully realized on these graphs, and their topological similarity on the differentiation process of the CCL. The construction principle of the CCL also has been reviewed along with the toplogical and stereochemical compatibility of kernel and periphiral CCLs. The SBU, TBU and SSU criteria already proposed are realized on the construction process of the CCL. A possibility is suggested that the diversity of zeolite frameworks can be interpreted in terms of the local topology and geometry of 2nd CCLs only.
Isoscattering point is the specific point at which X-ray or neutron scattering intensity of solutes is independent of contrast between solutes and solvent. The point has been observed in the X-ray small-angle scattering curves of globular particles such as micelles and bacteriophages. The condition for appearance of the Isoscattering point is briefly summarized and in view of the application to analysis of the solute structures, the nature of the isoscattering point is described in detail.