Correlated N/O anion orders in melilite phosphors
Journal
Journal of Solid State Chemistry
Journal Volume
284
Date Issued
2020
Author(s)
Abstract
The N/O anion distributions in the melilite-type phosphor host material Y2Si3O3N4 and a Ce-doped sample Y1.5Ce0.5Si3O3N4 have been determined from powder neutron diffraction. Both materials have a highly ordered N/O distribution that is not changed significantly by the disorder introduced by Ce doping. This distribution evidences the presence of SiN3O and SiN2O2 tetrahedra and although these are not fully long range-ordered, local structural correlations follow simple connectivity rules that lead to an estimated residual molar entropy of R ln3. A broad range of N/O environments is found around 8-coordinate Y(Ce) sites which is expected to broaden their spectroscopic features. ? 2020 Elsevier Inc.
Subjects
Ions; Light emission; Phosphors; Silicon compounds; Yttrium compounds; Anion distribution; Anion ordering; Host materials; Molar entropies; Oxynitrides; Powder neutron diffraction; Spectroscopic features; Structural correlation; Nitrogen compounds
Type
journal article