Preparation and characterization of NiFe
2
O
4
nanoparticles
P. Sivakumar
1
, R. Ramesh
2
, A. Ramanand
1
, S. Ponnusamy
2
and C. Muthamizhchelvan
2
1
Department of Physics, Loyola College, Nungampakkam, Chennai – 600 034, Tamilnadu, India.
2
Center for materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur, Chennai – 603 203,
Tamilnadu, India.
E -mail: p_siva1978@yahoo.co.in
Received 20 October 2010
Revised 19 January 2011
Accepted 8 February 2011
Online at www.springerlink.com
© 2011 TIIM, India
Abstract
Ni-Ferrite (NiFe
2
O
4
) nanoparticles haves been synthesized by simple and low cost co-precipitation technique. The synthesized product was
characterized by X-ray diffraction (XRD), High resolution scanning electron microscopy (HRSEM) and vibrating sample magnetometry (VSM).
The XRD and HRSEM results showed that the average particle size of the synthesized product was 20 – 25 nm with inverse spinel structure.
The morphology of as synthesized product was in spherical shape. The existence of ferromagnetic properties was confirmed by VSM.
1. Introduction
Spinel structured magnetic iron oxide nanoparticles,
MFe
2
O
4
(where M is a divalent cation such as Ni
2+
, Mn
2+
etc.,) and their dispersions in various media have long been
of scientific and technological interest. By varying the
chemical identity of M
2+
, the magnetic configurations of
MFe
2
O
4
can be molecularly engineered to provide a wide
range of magnetic properties. Partly because of this
versatility, nanometer-scale NiFe
2
O
4
materials have been
among the most frequently chosen systems for studies of
nanomagnetism and have shown great potential for many
important technological applications. For example magnetic
recording media, magnetic resonance imaging, ferrofluid,
magnetic fluids, drug delivery system, catalysis and gas
sensors [1]. Various techniques such as co-precipitation [2],
sol-gel [3] and hydrothermal technique [4] have been
developed for synthesis of nanosized metal ferrites. Among
these techniques co-precipitation technique is low cost,
environmental friendly and the experiment can be carried out
at room temperature.
In the present work we report the synthesis of Ni-Ferrite
by wet chemical method. The synthesized samples were
characterized using XRD, HRSEM and VSM.
2. Materials and method
All the chemical reagents were analytical grade and
used without further purification. Double distilled de-ionized
water was used as a solvent. Manipulations and reactions
were carried out in air without the protection of nitrogen or
inert gas.
In a typically synthesis, a 0.4 M (20 mL) solution of iron
nitrate (Fe(NO
3
)
3
·9H
2
O) and a 0.2 M (20 mL) solution of
nickel nitrate (Ni(NO
3
)
2
·6H
2
O) were mixed in de-ionized
water. A specified amount of Polyvinyl Propylene (PVP) was
added to the solution as a surfactant and coating the material.
Keywords:
Ni-Ferrite; magnetic nanoparticle; co – precipitation; VSM
A 5 ml solution of hydrazine hydrate (NH
2
.NH
2
.H
2
O) was
slowly added to the salt solution in drop wise. The reactants
were constantly stirred using a magnetic stirrer. The liquid
precipitate was then brought to a reaction temperature of
80°C and stirred for 2 h. The product was then cooled to
room temperature. The precipitate was subsequently
centrifuged with ethanol and de-ionized water three times.
Finally, the product was dried in a hot air oven at 100°C for
4 h. The final sample was then confirmed by different
techniques, such as XRD, HRSEM and VSM.
2.1 Characterization
X-ray diffraction pattern of the sample was recorded on
a PAN alytical X’ pert pro X-ray diffractometer using Cu K
radiation (1.5406Å) source. The intensity data were collected
over a 2 range of 20 – 80° using a step scan mode
(0.06°/s).
Microstructural characteristic such as morphology,
particle size and crystal structure of the samples were
analyzed by High Resolution scanning electron microscope
(HRSEM) (FEI Quanta FEG200).
The magnetic measurement was carried out in a vibrating
sample magnetometer (VSM, JDM - 13) at room temperature.
3.Results and discussion
The powder XRD pattern of NiFe
2
O
4
sample prepared
by co-precipitation method is shown in Fig. 1. The powder
XRD pattern of the sample wad significantly broader than
those for a micrometer sized sample, indicating a very small
particle size [5]. The crystallinity and structure of the NiFe
2
O
4
nanocrystals were also confirmed by powder XRD (The XRD
patterns of the sample agree well with the powder diffraction
file of JCPDS file No. 10-0325 [6]. The space group of the
material is Fd3m and it has inverse spinel structure. All the
characteristic peaks of NiFe
2
O
4
are present at 30.47° (220),
Transactions of The Indian Institute of Metals
Vol. 64, Issues 1 & 2, February-April 2011, pp. 233-234
TP 2476