Résumé:
Nickel
–
copper ferrites with th
e general formula Ni
1
x
Cu
x
Fe
2
O
4
(0
r
x
r
1) were studied using X-ray diffraction and infrared absorption spectroscopy.
XRD diffraction patterns show that all
samples have a pure single-phase cubic spinel structure over the whole composition range. From these patterns
,the
lattice parameters, crystallite size an
d porosity of these samples have been calculated and com
pared with those predicted theoretically. Most of th
evalues
were found to increase with increasing Cu content. Far infrared absorption spectra show high and low absorption bands co
rresponding to tetrahedral a
nd
octahedral sites con
fi
rming the single phase spinnel structure. The calculated force constants,
K
t
and
K
o
for the two sites are found to increase with
increasing Cu content and their relative values are consistent w
ith bond length magnitudes at tetra
hedral and octahedral sites.
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&
2014 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.
