A silica zeolite (RWZ-1) with a very high framework density (FD) was synthesized from highly crystalline natural layered silicate magadiite, bridging the gap between the two research areas of zeolites and dense silica polymorphs. Magadiite was topotactically converted into a 3D framework through two-step heat treatment. The resulting structure had a 1D micropore system of channel-like cavities with an FD of 22.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
April 2022
The structure refinement and XANES study of two gold-silver-tellurides [AuAgTe, krennerite (x = 0.11-0.13) and sylvanite (x = 0.
View Article and Find Full Text PDFStudy of arsenic (As) provides guidelines for the development of next-generation materials. We clarify the unique structure of the third crystalline polymorph of natural As (Pnm2-As) by crystallographical experiment and the electronic structure by first-principles computational method. The crystal structure of Pnm2-As is a novel structure in which the basic portions of semi-metalic grey-As and semi-conductor black-As are alternately arranged at the atomic level.
View Article and Find Full Text PDFA synchrotron X-ray diffraction study of a single crystal of titanomagnetite shows that the cation distribution of Fe, Fe and Ti is of the inverse-spinel type. The valence-difference contrast (VDC) method of resonant scattering was applied at a wavelength of λ = 1.7441 Å (E = 7.
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