The plots above show the PDF’s of four systems for comparison, where each peak in a PDF corresponds to an interatomic distance in the solid. This data was collected at 60 keV in a matter of minutes, highlighting the excellent quality that can be obtained at I15. It is readily clear that the peaks associated with the aluminosilicate framework, such as that at ~1.7 Å due to the (Si,Al)-O bonds, are essentially the same for all patterns but others change dramatically as a function of cation. This is more readily seen below, comparing the PDF’s of the hydrogen form of zeolite A and a specially prepared sample of the Zn form of A. Work is now underway to build a model for the Zn system, a problem that has not yet been tractable using traditional crystallographic analysis with powder diffraction data.
Aucun commentaire:
Enregistrer un commentaire