By a solid state reaction of LaN, Eu2O3 and Si3N4, LaSi3N5, La0.9Eu0.1Si3 N
5-XOX and LaEuSi2N3O2 were prepared at 1900 degrees C for 2h under 1.01 x 1
0(6) N m(-2) nitrogen pressure. These compounds were identified by X-ray di
ffraction analysis, and then characterized by means of absorption and lumin
escence spectroscopies. La0.9Eu0.1Si3N5-XOX was isostructural with LaSi3N5.
For only La0.9Eu0.1Si3 N5-XOX, we observed a broad emission band with a ma
ximum at 549 nm due to the 4f(6)5d --> 4f(7) transition of Eu2+. On the oth
er hand, the Eu2+ ion in LaEuSi2N3O2 showed a deep-red emission band at 650
nm. (C) 2000 Elsevier Science B.V. All rights reserved.