Zn Nano-Ferrites Prepared By Citrate-Gel Auto Combustion

Document technical information

Format pdf
Size 463.4 kB
First found Nov 13, 2015

Document content analysis

Language
English
Type
not defined
Concepts
no text concepts found

Organizations

Places

Transcript

D. Ravinder et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.137-141
RESEARCH ARTICLE
www.ijera.com
OPEN ACCESS
Synthesis and Structural Characterization of Cu Substituted NiZn Nano-Ferrites Prepared By Citrate-Gel Auto Combustion
Technique
N. Hari Kumar1, G. Aravind1, D. Ravinder1*, T.Somaiah2, B. Ravinder Reddy3
1
Department of Physics, Osmania University, Hyderabad, 500007-India.
Department of Physics, Engineering College, Osmania University, Hyderabad, India
3
Dept of Physics, College of Technology, Osmania University, Hyderabad, India.
2
Abstract
The ferrite nano particles having chemical formula Ni0.2CuxZn0.8-xFe2O4 (where x=0.0 to 0.8 with step of 0.2)
were synthesized by Citrate-Gel Auto Combustion method at low temperature. The synthesized powders were
sintered at 500oC for 4 hours in air and characterised by XRD, SEM with EDS. XRD analysis of prepared
samples were confirmed the single phase cubic spinel Structure. The crystallite size (D) of prepared ferrites
were in the range of 24-73nm. The values of lattice parameter (a) decreased and X-ray density (dx) were
increased with the increasing of Cu substitution. The surface morphology of the prepared samples was
investigated by Scanning Electron Microscope(SEM). An elemental composition of the samples was studied by
Energy Dispersive Spectroscopy(EDS). The observed results can be explained on the basis of composition and
crystal size.
Keywords: Ferrites, Citrate-Gel Auto Combustion method, XRD, SEM, EDS.
I. INTRODUCTION
Nano materials have been produced and used by
humans for hundred of years, however the
understanding of certain materials as a nano
structured materials is relatively recent made possible
by the advant of advanced tools, that are capable of
resolving information at nano scale. The properties of
ferrites are sensitive to synthesis method, synthesis
conditions, synthesis parameters, nature and type of
substitution and cation distribution. Ferrites are very
important and widely used materials in technical
desining and applications at high frequencies[1]. One
of the most important advantages of ferrites is their
very high degree of compositional variability.
Nanoparticles of ferrites are very important group of
magnetic materials due to their extensive use in a
wide range of applications. The properties of nano
materials are remarkably different from that of their
bulk counterpart. The interest in ferrite nano particles
is due to their important physical and chemical
properties and potential for various technological
applications such as high density magnetic storage,
electronic and microwave devices, sensors,
magnetically guided drug delivery. The transport
properties of the nano particles are predominately
controlled by the grain boundaries than by the grain
itself.[2]. In order to achieve a high degree of
molecular mixing , chemical homoginity, control of
stoichiometry, low calcination and sintering
temperature/time, various chemical methods have
been used for the synthesis of spinel ferrites[3-6]
www.ijera.com
several researchers have reported the synthesis of NiZn-Cu ferrites using different techniques like
reffluxing process[7], ceramic method [8],
hydrothermal method [9], combstion method[10],
coprecipitation
method[11],
reverse
micelle
process[12], spark plasma sintering[13].Micro
emulsion method [14] and ball milling method etc.
In the present work we reported the results of
synthesis and structural properties of Ni-Cu-Zn
ferrites by non conventional citrate gel auto
combustion method.
II. Experimental
2.1 Synthesis: The composition of Ni-Cu-Zn ferrite
particles having chemical formula Ni0.2CuxZn0.8xFe2O4 (where x=0.0 to 0.8 with step of 0.2) were
synthesized by Citrate-Gel Auto Combustion method
at lower temperature. Nickel Nitrate, Cupper nitrate,
Zinc Nitrate, Ferric Nitrate,Citric acid and
ammonia(all chemicals are 99% pure AR Grade
SDFCLsd fine chemical limited) are the raw
materials for the synthesis process. Calculated
quantities of metal nitrates and citric acid were
dissolved in minimum amount of distilled water to
get clear solution. Here citric acid acts as a chelating
agent and helps in the homogeneous distribution of
metal ions. The above mixture was stirred to get
homogeneous clear solution which is heated to 80 oC
using a hot plate magnetic stirrer. Then the pH of the
solution is adjusted at 7 by addition of ammonia. A
sol is formed. The resulting solution was evaporated
137 | P a g e
D. Ravinder et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.137-141
to dryness heating at about 180OC on a hot plate with
continuos stirring. The gel gave a fast flameless auto
combustion reaction with the evolution of large
amount of gases which results a burned powder. The
burned powder was grinding using Agate Mortar and
pestle to get a fine ferrite powder. Finally the grinded
powder was calcinated in air at 500OC for 4 hours
and cooled to room temperature to obtain spinel
phase.
www.ijera.com
crystalline size of all samples was calculated from the
Half Width at Full Maximum (HWFM) of the (311)
reflection peak in the XRD pattern using DebyeScherrers formula[15].
Scherrer Formula:
   ℎ   =
. 
 
Where λ =wavelength of X-ray used
Β=
Full
Width
Half
Maxima(FWHM) in radians.
θ = peak position.
Lattice parameter(a) of the sample was calculated by
the formula
1
 =  ∗ (ℎ2 +  2 +  2 ) 2
Where a= Lattice Constant
(hkl) are the Miller Indices
d = inter planner spacing,

The X-ray density  =  [g/cm3] [16]
 
Where M = molecular weight of the sample
n =number of molecules in a
unit cell of spinel lattice.
a =lattice parameter and N is the
Avogadro number.
The Volume of the Unit Cell V= a3
2.2
Characterization: BrukerD8 advanced Xray diffractometer with Cu Kα (λ= 1.5405AO) was
used to study the single phase nature and nano phase
formation of the Ni-Cu-Zn ferrite system at room
temperature by continuos scanning in the range of
10o-80oC. Micro structure analysis of the prepared
samples was carried by Scanning Electron
microscopy(SEM) and Elemental compositional
analysis for all samples were done by Energy
Dispersive Spectroscopy(EDS).
III. Results and Discussions:
Intensity(Counts)
0
10
20
30
40
50
60
440
422
511
400
222
220
111
311
3.1 XRD Analysis: the X-ray Diffraction pattern of
all the samples were shown in fig(1) which confirms
the single phase cubic spinal structure formation with
out any impurity peak. The strongest reflection has
come from (311) peak for every sample. The
5
70
80
90
4
0
10
20
30
40
50
60
70
80
90
3
0
10
20
30
40
50
60
70
80
90
2
0
10
20
30
40
50
60
70
80
90
1
0
10
20
30
40
50
60
70
80
90
2
Fig(1).XRD Pattern of Cu Substituted Ni-Zn Nano-Ferrites
Values of Crystallite size, lattice parameter, X-ray density and volume of all the samples were given in the
table(1).
www.ijera.com
138 | P a g e
D. Ravinder et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.137-141
Table(1): Crystalline size,Lattice Parameter, X-ray density &Volume
S.N
Sample
Mol.wt
Crystallite
Lattice
o
(gm/mol)
size(nm)
constant
(Ao)
1
Ni0.2Zn0.8 Fe2O4
239.735
54.27
8.407
2
Ni0.2Cu0.2Zn0.6Fe2O4
239.368
54.58
8.406
3
Ni0.2Cu0.4Zn0.4 Fe2O4
239.002
54.76
8.386
4
Ni0.2Cu0.6Zn0.2 Fe2O4
238.635
72.35
8.379
5
Ni0.2Cu0.8 Fe2O4
238.268
24.13
8.313
From the table we can observe that the crystallite
size of the prepared samples were in the range of
24.13nm to 72.35nm. Lattice parameters of the
prepared samples were decreased by increasing the
Cu concentration which obeys the Vigurd’s law [17].
The observed decrease in the crystallite size can be
explained by on the basis of relative ionic radii of Cu
and Zn ions.
As Cu+2(0.73Ao)Ionic radius is smaller than that
of the Zn+2(0.74 Ao). X-ray density of the prepared
samples were observed to be increased with
increasing the Cu concentration since X-ray density
of the sample depends upon the molecular weight and
lattice parameter. From the table we can observe that
lattice parameter of the samples were decreases so Xray density should be increased. Volume of the unit
cell was also depends on lattice parameter. Lattice
www.ijera.com
X-ray
density
(gm/cc)
5.349
5.360
5.381
5.386
5.507
Volume
(Ao)3
594.186
593.974
589.745
588.269
574.477
parameter of the prepared samples were decreased so
the volume of the unit cell also decreased
3.2 SEM ANALYSIS:
Micro structural analysis of the prepared
samples was carried out by Scanning Electron
Microscopy(SEM). The SEM micrographs of the
prepared samples were shown in below fig(2). The
SEM micrographs shows that the grains have almost
homogeneous distribution and clusters between the
particles. The grain size of the samples lies in the
nano meter region have a spherical shape and narrow
size distribution. SEM image revealed that with
increasing in the Cu concentration, then the grain size
has increased (except for x=0.8) which is an evidence
for the XRD analysis
Fig(2).SEM Micrographs of Ni-Cu-Zn Nano ferrites
3.3 ELEMENTAL ANALYSIS BY EDS:
www.ijera.com
139 | P a g e
D. Ravinder et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.137-141
www.ijera.com
Energy Dispersive Spectrometer was used for the elemental analysis of all the prepared ferrites with
different compositions. The EDS spectra of all prepared samples were shown in fig(3).The compounds show the
presence of Cu,Zn, Ni,Fe,O with out precipitating cations.
Fig (3).EDS Spectra of Ni-Cu-Zn Nano ferrites
IV. Conclusions
i) X-ray diffraction pattern of the prepared samples
confirms the formation of single phase cubic spinal
structure
ii) By the substitution of Cu in the Ni-Zn ferrite
system, the lattice parameter is decreases and the
crystallite size of the sample was in the range 24-72
nm.
iii)X-ray density of the samples increases with Cu
Substitution.
iv) SEM micrographs of the various compositions
indicate the morphology of the particles was similar.
They are largely agglomerated.
V. Acknowledgements
The
authors
are
very
grateful
to
Prof.K.Venugopal Reddy, Head, Department of
Physics, University College of Science, Osmania
University, Hyderabad, Prof.R.Sayanna, Chairman,
Board of Studies, Department of Physics, University
College of Science, Osmania University, Hyderabad,
Prof.ChintaSailu,Principal,CollegeofTechnology,
www.ijera.com
Osmania University, Hyderabad and Prof.Ch.Gopal
Reddy,Head,DeptofPhysics,EngineeringCollege,Osm
aniaUniversity,Hyderabad for their encouragement in
research work.
REFERENCES
[1]
M.Pardavi-Horvath, J Magn Magn Mater
215/216, 171 (2000)
[2]
T. Abbas, Y.Khan, M.Ahmed, S.Anwer,
solid state communi 82 (1992)701
[3]
P.K.Roy and J.Bera, J Magn Magn mater
298,38,(2006)
[4]
P.D.Thang, G.Riginders and D.H.Blank, J
Magn Magn mater296,251(2005)
[5]
M.F.F.lelis , A.O.Porto, C.M.goncalvers,
and J.D.Fabris, J J Magn Magn
mater278,263 (2004)
[6]
M. K. Kumar, P.K.Singh, P.Kishan, N.
kumar, S.L.N.Rao, P.K.Singh, and S.L.
Srivathsava J.Appli Physics,63,3780 (1998 )
[7]
A.Dias, and R.L.Moreira, chemical,
mechanical and dielectric properties after
sintering of hydro thermal ni-Zn Ferrites.
140 | P a g e
D. Ravinder et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.137-141
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
www.ijera.com
Mat Letters Vol 39 num 1,1999, pp69-76
doi;10.1016/ s/ 0167-5777X(98)00219-5
S.E. Jacobo, s, Duhalde and H. R.Bertorello
“ Rare earth influencre on the structural and
magnetic properties of Ni-Zn Ferrites” J of
Mag and Mag Matrels Vol 272-276 N0 3,
2004pp 2253-2254
Doi:10.1016/j.jmmm.2003.12.564
S.D.Shenoy,P.A.Joy
and
M
.R
Anantharaman” effect of mechnical milling
on the structural, magnetic and dielectric
properties of Co-precipitated ultrafine Zn
ferrite,J of Magn Magn mater Vol269,No
2,2004,pp217-226 doi
10.1016/S03048853(03)00596-1
S.A.Morrison, C.L. Cahill, E.E. Carpenter,
S.Calvin, R.S waminnathon, M.E. McHenry
and V G Harris Magnetic And Structrural
Properties of Ni-Zn Ferrite nano particles
synthesised by At room temperature J of
Applied physics, Vol95,no 11 2004,
pp.6392-6395 doi 10.1063/1.1715132
J.Sun, J Li, G.Sun and W.Qu, synthesis of
densy Ni-Zn ferrites by Spark plasma
sintering , ceramics internation vol 28,No 8 ,
2002 pp 855-858 doi 10.1016/S02728842(02)00064-0
A.Verma, T.C,Goel, R.G.Mendiratta and
M.I.Alam,dielectric properties of Ni-Zn
ferrites by the citrate precursor method
“Materials
science
and
Engg.B
Vol60,2,1999 pp156-162 doi 10.1016/s0921
-5107(99)00019-7
G.P.Lopez, S.Psilvetti, S.sE. Urreta and E.D.
Cabanillas, Magnetic interaction in high
energy ball milled Ni-Zn ferrite/SiO2
composites “Physics B, Vol 398, No 2,2007
pp241-244doi 10.1016/J.PhysB.2007.04.024
C.Upadhya, D.Mishra, H.C.Verma, S.Anand
and R.P Das, effect of preperation
conditions on formation of nano phase NiZn ferrotes through Hydro thermal
technique J of mag Mag mater Vol 260,No
1-2, 2003,pp188-194 doi 10.1016/S03048853(02)01320-3
B.D. Cullity elements of XR Diffraction
Addision wesely publishing reading 1959
p132
R. C. Cumbale, P.A.Sheikah, S.S.camble
and Y. D. Kolekar effect of cobalt
substitution on structural magnetic and
electric properties of nickel ferrites. J Of
Alloys and Compound Vol478.n0 1-2, 2009
pp
599603,doi10.1016/J.Jmmm.2005.03.007
L. Vegard, Constitution of mixed crystals
and the space occupied by atoms, Zeitsch
rift ftir physics Vol5, No17.1921.pp17-23
www.ijera.com
141 | P a g e

Similar documents

×

Report this document