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Submitted on 1 Jan 1980
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ZERO AND HIGH FIELD MÖSSBAUER
SPECTROSCOPY STUDY OF THE MAGNETIC ORDERING AND LOCAL COORDINATION
ENVIRONMENT OF Fe2(PO4)Cl
C. Nicolini, W. Reiff
To cite this version:
C. Nicolini, W. Reiff. ZERO AND HIGH FIELD MÖSSBAUER SPECTROSCOPY STUDY OF THE MAGNETIC ORDERING AND LOCAL COORDINATION ENVIRONMENT OF Fe2(PO4)Cl.
Journal de Physique Colloques, 1980, 41 (C1), pp.C1-287-C1-287. �10.1051/jphyscol:19801101�. �jpa-
00219582�
JOURNAL DE PHYSIQUE
Colloque Cl , suppldment au n "
1 ,Tome 41, janvier
1980,page
C1-287ZERO AND HIGH FIELD ~ S B A U E R SPECTROSCOPY STUDY OF
THE
FnAGNETIC ORDERING AM) LOCAL COORDINATION ENVIRONEENT OFF~,(w,)c~
C. Nicolini and W.M. Reiff
Chemistry Dept., Northeastern University, Boston, and E. Kostiner, I . of MateriaZs Sc., U . of Connecticut, Storrs,. USA.
I n t h i s work we present a Miossbauer study o f t h e magnetic o r d e r i n g o f ~ e ~ ( P 0 ~ ) C l , a t w i s t e d zigzag c h a i n whose s t r u c t u r e has been r e c e n t l y d e t e r - mined. (') The c h a i n i s based on t h e t r i n u c l e a r u n i t shown, ( F i g . 1 ) w i t h t h r e e c r y s t a l l o g r a p h i c a l - l y unique Fe atoms, such t h a t Fel corresponds t o an unusual, adjacent f a c e s h a r i n g M04C12 octahedron and Fe* and Fe3 are edge s h a r i n g octahedra. The Mossbauer spectra d i s t i n g u i s h a t l e a s t 2 o f these environments a t ambient temperature and a t 77OK.
A f r a c t i o n o f t h e i r o n e x h i b i t s r e s o l v e d magnetic F i g h y p e r f i n e s p l i t t i n g a t 40.13K (Fig. 2). The r e -
do
1. The s t r u c t u r a l u n i t o f Fe2(PO4)C1 (From r e f . 1 ).
maining paramagnetic f r a c t i o n p e r s i s t s u n t i l t h e temperature i s decreased t o c 6K below which a l l o f t h e Fe show magnetic h y p e r f i n e s p l i t t i n g c o r r e - sponding t o a Hhf c 354kG. From t h e L o r e n t z i a n f i t o f t h e spectrum a t 40.13K t h e r a t i o o f t h e area o f t h e h y p e r f i n e s p l i t phase t o t h e r a p i d r e l a x i n g phase i s 2/1 and r e l a t i v e t o t h e s t r u c t u r e i t appears t o i n d i c a t e t h a t i t i s F e ( l j t h a t i s n o t h y p e r f i n e s p l i t . These observations c o r r e l a t e w i t h t h e temperature and f i e l d dependences o f t h e magnetic s u s c e p t i b i l i t y which e x h i b i t s complex AF behavior w i t h d i s t i n c t maxima i n
xi
vs T a t 7.8OK and 61 .g°K. Fe(1) appears t o be o r d e r i n g a t lower temperature. We observe s i m i l a r complex behaviors i n s u s c e p t i b i l i t y s t u d i e s o f t h e r e l a t e d Cu- and Co-chloroarsenate systems 2 (Cu2(As04)C1 andCo2(As04)C1) two and t h r e e maxima i n
x,,,
vs T r e s p e c t i v e l y . 3h o r k supported by NSF-DMR-77-12625
Velocity (mrnlsec) Relative to Iron
Fig. 2 Mbsbauer spectrum of Fe2(P04)C1 a t 40.13K.
/1/
J.B.
Anderson,J.R.
Rea andE.
K o s t i n e r , Acta Cryst.B32,
(1976), 2427/2/
J.R.
Rea,J.B.
Anderson and E. Kostiner, Acta Cryst.833,
(1977); 975./3/ C. N i c o l i n i , G. Eisman, W.M. R e i f f and E. Kostiner, Proc. I n t . Conf. Magnetism Munchen, Sept. 1979.
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19801101
