Instrumentation and measurementsPow

Instrumentation and measurements
Powder X-ray diffraction (XRD) patterns for the resultant powders of
CaAlSiN3:Eu2+ phosphor were measured on the RIGAKU RINT2200 diffractometer
using monochromated CuKa radiation which was operated at 40 kV and 30 mA,
together with the powders of (Ca,Eu)AlSi and (Ca,Eu)AlSiHx starting materials.
The lattice parameters and cell volumes were calculated from the recorded XRD
patterns by using a DICVOL program [22] and Rietveld refinement was performed
by a FULLPROF SUITE program [23,24] based on a pseudo-Voigt function as a peak
shape. For the Rietveld analysis, a set of reflections in a range of 20–80 as measured
with a step of 0.01 in 2h were individually considered for the calculation and
refinement. Oxygen and nitrogen contents of the CaAlSiN3:Eu2+ phosphors were
measured on an HORIBA EMGA-550 oxygen/nitrogen analyzer. The particle shape
and size of such powders were observed on a scanning electron microscopy
(SEM, HITACHI S-3000). The photoluminescence spectra of them were also measured
at room temperature on a HITACHI F-4500 fluorescence spectrometer in a
range of 200–800 nm with a scanning speed of 240 nm/min. For comparing their
luminescence properties, a commercially-available YAG:Ce3+ phosphor (P46-Y3,
KASEI Optonix) was used as a reference.