Structural determination of high-pressure AlPO<sub>4</sub> phases by NMR and powder X-ray diffraction techniques

DOI

Bibliographic Information

Other Title
  • NMRと粉末X線回折法によるAlPO<sub>4</sub>高圧相の構造解析

Abstract

High-pressure quench experiments of AlPO4 revealed two new polymorphs at 6-7 GPa. "I" stabilized at 1000°C, and "II" stabilized at 1500°C. 31P MAS NMR revealed three tetrahedral P sites of equal abundances in each phase. 27Al MQ MAS NMR unveiled two octahedral and one penta-coordinated Al sites for each phase. We solved the crystal structures using the "FOX" program (direct-space searching method), using the information from NMR to constrain the number and types of polyhedra. The space group of I was P-1, whereas, that of II was P21/c. The length of a- and c-axes are similar, however, that of b-axis of II was about twice of that of I. The densities of two phases are almost the same, and are 28% larger than that of quartz phase. Both phases contain short chains made of edge-shared six Al-polyhedra which are interconnected by PO4 tetrahedra to form 3D network.

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Details 詳細情報について

  • CRID
    1390001205545362816
  • NII Article ID
    130004601288
  • DOI
    10.14824/jakoka.2009.0.127.0
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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