Tridymite

About: Tridymite is a research topic. Over the lifetime, 840 publications have been published within this topic receiving 14831 citations.

The systematic enumeration of (4;2)-connected 3D nets related to the tridymite group

Abstract: Forty-two hypothetical 3D nets are derived by applying four types of transformations (or combinations thereof) to the previously described tridymite group of structures. Two novel transformations are proposed, one preserving the (hexagonal or orthorhombic) symmetry and another converting the hexagonal symmetry into orthorhombic. Correspondingly, groups of hypothetical 3D framework structures are derived. The properties of frameworks belonging to these groups are compared and discussed.

Liquid phase deposition of iron phosphate thin films

Abstract: Liquid phase deposition (LPD) has been applied for the synthesis of iron phosphate thin films as an example of an effective methodology for the thin film growth of other polyanionic compounds The prepared films were highly uniform, free of cracks, pure and successfully applied to cover various substrates such as soda-lime glass and stainless steel The thickness of these films can be easily tailored in the range of 80 nm to 27 μm by the deposition time The chemical equilibria for the hydrolysis of [PF6]− species and the formation of iron phosphate were studied by 19F-NMR and 31P-NMR spectroscopy to get insight into the formation mechanism of iron phosphate thin films Hydrolysis of [PF6]− occurs very slowly and a longer induction period favors the hydrolysis The as-prepared FePO4·2H2O films on conductive stainless steel substrates are shown to be electrochemically active for the intercalation of Li+ ions Two polymorphs of FePO4 with crystal structures identical to hexagonal tridymite AlPO4 and monoclinic FeAsO4 were identified upon heat treatment of the as-prepared powders

Structural changes and microstructures in stuffed tridymite-type compounds Ba1−xSrxAl2O4

Abstract: Crystal structures and microstructures in Ba1−xSrxAl2O4 solid solutions between the end members of BaAl2O4 and SrAl2O4 have been carefully investigated by powder X-ray diffraction, electron diffraction and transmission electron microscopy (TEM) imaging experiments. With the help of fast Fourier transform (FFT) calculation, high-resolution TEM images suggested that diffuse streaks along three equivalent 〈110〉 directions in the (001) plane, which appear in the P63 structure of Ba1−xSrxAl2O4 for x = 0.4, originate from the large structural fluctuation of the AlO4 tetrahedral network. On the other hand, the monoclinic P21 structure in Ba1−xSrxAl2O4 with x = 0.7 was found to consist of a modulated structure with . The present experimental results reveal that a structural phase boundary exists at approximately x = 0.6 between the P63 structure with a large structural fluctuation and a monoclinic P21 phase with the single-q modulated structure.