ISSN:
1551-2916
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Maschinenbau
,
Physik
Notizen:
Cerium-doped α-SiAlON (MxSi12−(m+n)Alm+nOnN16–n) materials have been prepared by gas-pressure sintering and post-hot-isostatic-press (HIP) annealing, using four powder mixtures of α-Si3N4, AlN, and either (i) CeO2, (ii) CeO2+ Y-α-SiAlON seed, (iii) CeO2+ Y2O3, or (iv) CeO2+ CaO. Cerium-containing CeAl(Si6–zAlz)(N10–zOz) (JEM) phase, rather than Ce-α-SiAlON phase, forms in the sample with only CeO2, whereas a single-phase α-SiAlON generates in samples with dual doping (CeO2+ Y2O3 and CeO2+ CaO). On ultraviolet-light excitation, JEM gives one broad emission band with maximum at 465 nm and a shoulder at 498 nm; α-SiAlON shows an intense and broad emission band that peaks at 500 nm. The unusual long-wavelength emissions in JEM and α-SiAlON are due to increases in the nephelauxetic effect and the ligand-field splitting of the 5d band, because the coordination of Ce3+ in JEM and α-SiAlON is nitrogen enriched.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1151-2916.2004.tb07738.x
