Jan 1, 1987 - 607 and 51 4 nun shows remarkable differences. The spectrum excited by. 514 nm (this line excites Cr(II1) ion in the site B ) is similar to the.
BROAD-BAND EMISSION OF Cr3+ IN MgAl2O4 SPINEL W. Strek, P. Dere, B. Jezowska-Trzebiatowska
To cite this version: W. Strek, P. Dere, B. Jezowska-Trzebiatowska. BROAD-BAND EMISSION OF Cr3+ IN MgAl2O4 SPINEL. Journal de Physique Colloques, 1987, 48 (C7), pp.C7-475-C7-477. .
HAL Id: jpa-00226930 https://hal.archives-ouvertes.fr/jpa-00226930 Submitted on 1 Jan 1987
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est destin´ee au d´epˆot et `a la diffusion de documents scientifiques de niveau recherche, publi´es ou non, ´emanant des ´etablissements d’enseignement et de recherche fran¸cais ou ´etrangers, des laboratoires publics ou priv´es.
JOURNAL DE PHYSIQUE Colloque C7, supplement au n 9 1 2 , Tome 48, d6cembre 1987
BROAD-BAND EMISSION OF
W.
cr3'
IN MgA12 O4 SPINEL
STREK, P. DERE& and B. JEZOWSKA-TRZEBIATOWSKA
Institute for Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, PL-53529 Wroclaw, Poland
Abstract. The d o u b l e luminescence h e h a v i o u r of C r (111) i n s y n t h e t i c MgA1204 s p i n e l was o b s e r v e d . The n a t u r e o f s u c h a b e h a v i o u r i s i n v e s t i g a t e d by means t h e t i m e - r e s o l v e d luminescence s t u d i e s a t d i f f e r e n t e x c i t a t i o n w a v e l e n g t h s . It i s shown t h a t t h e broad-rbroad e m i s s i o n ob2 QAp s e r v e d . i n s y n t h e t i c s p i n e l i s d u e t o t h e spin-allowed 4 ~ + fluorescence t r a n s i t i o n . Introduction
-
The C r (111) i o n o c c u p i e s a d i s t i n g u i s h e d p o s i t i o n o n a l i s t of l a s i n g i o n s . The d o u b l e f o r b i d d e n phosphorescence
-
2
E
4A2 was f o r t h e
f i r s t t i m e u t i l i z e d f o r l a s e r o p e r a t i o n i n ruby. R e c e n t l y t h e s p i n a l ' T2 lowed 7
4A2 f l u o r e s c e n c e was u t i l i z e d f o r t u n a b l e s o l i d s t a t e
l a s e r s [ l -21. field
Dq/B
5
I t o c c u r s i n m a t e r i a l s c h a r a c t e r i z e d by low l i g a n d
2.3
.
I n t h i s p a p e r we r e p o r t t h e luminescence measurements o f C r (111) i n s y n t h e t i c MgA120,+s p i n e l . We have found t h a t t h i s c r y s t a l i n c o n t r a s t t o t h e n a t u r a l s p i n e l [3 I e x h i b i t s a broad band luminescence o r i g i n a t i n g from t h e 4 ~ s2 t a t e . Results The r e s u l t s of e a r l i e r works [ 4 , 5 ]
on t h e o p t i c a l p r o p e r t i e s o f
C r (111) i n s y n t h e t i c MgAl2O4 s p i n e l i n d i c a t e t h a t t h e C r (111) i o n
s u b s t i t u t e s two c r y s t a l l o g r a p h i c s i t e s i n t h i s c r y s t a l . The luminesc e n c e s p e c t r a of C r (111) i n MgA1204 measured a t room t e m p e r a t u r e and
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19877113
J O U R N A L DE PHYSIQUE
C7-476
F i g . 1. Luminescence s p e c t r a o f C r (111) i n N.gA12011 a t 3 00 K . under d i f f e r e n t e x c i t a t i o n wavelengths a r e shown i n F i g . 1 . One c a n n o t e t h a t t h e s p e c t r a r e c o r d e d f o r t h e e x c i t a t i o n wavelengths 607 and 51 4 nun shows r e m a r k a b l e d i f f e r e n c e s . The spectrum e x c i t e d by 514 nm ( t h i s l i n e e x c i t e s C r ( I I 1 ) i o n i n t h e s i t e B ) i s s i m i l a r t o t h e annealed n a t u r a l s p i n e l whereas t h e spectrum e x c i t e d by 607 nm ( t h i s l i n e i s a d j u s t e d t o e x c i t e t h e second s i t e A ) i s c h a r a c t e r i z e d by broad band e m i s s i o n c e n t e r e d a t 13 8 0 0 an-'.
The s p e c t r u m e x c i t e d by
488 nrn combines t h e f e a t u r e s o f b o t h t h e former o n e s . To g e t i n s i g h t
i n t o t h e n a t u r e of d o u b l e luminescence b e h a v i o u r o f C r (111) i n MgA1204 we h a ' ~ e performed t h e luminescence measurements up t o 600 K.
The v a r i -
a t i o n of luminescence decay t i m e s w i t h t e m p e r a t u r e s i s shown i n F i g . 2 .
Fig.
2.
The t e m p e r a t u r e dependence of luminescent e decay t i m e s o f C r (111) i n MgA120h
.
We have observed t h a t t h e decay t i m e s combined w i t h broad band emiss i o n were 6 -7
t i m e s s h o r t e r t h a n c o r r e s p o n d i n g t o narrow band emis-
s i o n . The t i m e v a r i a t i o n o f luminescence s p e c t r u m e x c i t e d by 488 nun ( s e e F i g . 3 ) c l e a r l y i n d i c a t e s t h a t t h e broad band e m i s s i o n i s f a s t e r quenched t h a n t h e narrow band. I n conclusion, t h e r e s u l t s presented h e r e i n i n d i c a t e t h a t t h e d o u b l e luminescence b e h a v i o u r of C r (111) i n s y n t h e t i c MgA1204 s p i n e l
i s ccnnbined w i t h two d i f f e r e n t C r (111) s i t e s . Whereas t h e C r (111) i n t h e s i t e s B g i v e s t h e spectrum s i m i l a r t o t h e n a t u r a l s p i n e l t h e C r (111) i n t h e i n v e r s e s i t e A g i v e s t h e broad band luminescence. T h i s
-
s i t e i s c h a r a c t e r i z e d by lower l i g a n d f i e l d [ 5 ] , which p r e f e r s t h e 4 ~ 2 A '
fluorescence.
2
P i g . 3 . Time - r e s o l v e d i n MgA1204
.
luminescence s p e c t r u m o f C r (111)
R e f e r enc e s 1.
2. 3.
J.C.
W a l l i n g , O.G.
E.W.
O t B e l l , IEEE J. Q u a n t . E l e c t r . QE 1 6 , 119, 1980.
J . Buchert and R.R.
P e t e r s o n , H.P.
A l f a n o , L a s e r Focus,
D.L.
W o d , G.F.
D.M.
L a t k i n , J . Chem. Phys.
4.
H.
5.
W.
J e n s s e n , P.C.
Imbusch, R.M.
Morris and
919, 1189, 1980.
McFarlane, P. K i s l u k and 48, 52, 1969.
van d e n Boom, A. J. J. v a n D i j s s e l d o n k and J . C .M.
J . Chern. Phys.
66, 2368, 1977.
S t r g k , P . Derefi a d B. Jeiowska-Trzebiatowska,
publication.
Henning, submitted f o r
