Novelty characterization and enhancement of magnetic properties of Co and Cu nanoferrites Ebtesam E. Ateia 1 • Asmaa A. El-Bassuony 1 • Galila Abdelatif 1 • Fatma S. Soliman 1 Received: 10 June 2016 / Accepted: 8 August 2016 / Published online: 11 August 2016 Ó Springer Science+Business Media New York 2016 Abstract Cobalt and copper nano ferrites synthesized by citrate technique were characterized by X-ray diffraction technique, field emission scanning electron microscopy, transmission electron micrographs, energy dispersive X-ray spectroscopy and atomic force microscope. The average crystallite sizes of Cu and Co were 24.7 and 37.7 nm respectively. The magnetic properties were studied by carrying out the hysteresis of MFe 2 O 4 (M-Cu 2? , Co 2? ) at room temperature and at 77 K. The data showed that CuFe 2 O 4 has the lower saturation magnetization. While CoFe 2 O 4 has the larger coercive field due to the high anisotropy of Co 2? ions. The variation in saturation mag- netization and coercivity for the investigated samples were explained on the bases of exchange interactions. The magnetic properties of the investigated samples changed at low temperature (77 K) which were observed in shape of the magnetic hysteresis M(H) loops as well as the coer- civity and the squareness values. Co samples will be hopeful for technological applications at or below room temperature. 1 Introduction Synthesis and application of magnetic nano particles with sizes of a few nanometers is a subject of intense research because of their interesting properties that make them attractive, both from the scientific value of understanding their properties, and the technological significance of upgrading the performance of the existing materials [1, 2]. Nanoferrites attracted considerable interest for a number of researchers, due to their promising technological importance in a wide range of applications, including photo catalysts [3, 4], magneto optical devices [5], high density magnetic recording [6] and so on. In the recent years, some researchers have investigated the effect of rare earth ions [7], and different surfactant [8], on the properties of nanoferrites. Generally, the physical properties of ferrites are sensitive to the valence state and distribution of cation over the tetrahedral (A-) and octa- hedral (B-) sites of the spinel lattice. Therefore, the infor- mation of cation distribution is essential to understand the different physical properties of spinel ferrites [9]. Despite a large portion spinel ferrites are cubic, copper ferrite (CuFe 2 O 4 ) can have tetragonal unit-cell symmetry if the sample is slowly cooled from high temperatures [10]. It can be designated as a cubic close-packed arrangement of oxygen ions with Cu 2? and Fe 3? ions at two different crystallographic sites [11]. Copper is an inverse ferro- magnetic spinel in which a small amount of Cu 2? ions migrate from octahedral B to tetrahedral A sites. On the other hand the spinel cobalt ferrite has a cubic symmetry and it has six crystallographic easy axes (directions) along the cube edges of the crystal represented as \ 100 [ and four crystallographic hard axes (directions) across the body diagonals denoted as \ 111 [ [12–14]. CoFe 2 O 4 shows some excellent physical properties such as high coercivity, chemical stabilities, moderate saturation magnetization, low conductivity and good mechanical and large magnetic anisotropy [15]. It is a hard magnetic material with a magnetic ordering temperature around 520 °C[16]. The importance of spinel nano ferrite in many applica- tions encourages us to through light on the properties of & Galila Abdelatif [email protected]1 Physics Department, Faculty of Science, Cairo University, Giza, Egypt 123 J Mater Sci: Mater Electron (2017) 28:241–249 DOI 10.1007/s10854-016-5517-y
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Novelty characterization and enhancement of magnetic propertiesof Co and Cu nanoferrites
Ebtesam E. Ateia1 • Asmaa A. El-Bassuony1 • Galila Abdelatif1 • Fatma S. Soliman1
Received: 10 June 2016 / Accepted: 8 August 2016 / Published online: 11 August 2016
� Springer Science+Business Media New York 2016
Abstract Cobalt and copper nano ferrites synthesized by
citrate technique were characterized by X-ray diffraction
technique, field emission scanning electron microscopy,
transmission electron micrographs, energy dispersive X-ray
spectroscopy and atomic force microscope. The average
crystallite sizes of Cu and Co were 24.7 and 37.7 nm
respectively. The magnetic properties were studied by
carrying out the hysteresis of MFe2O4 (M-Cu2?, Co2?) at
room temperature and at 77 K. The data showed that
CuFe2O4 has the lower saturation magnetization. While
CoFe2O4 has the larger coercive field due to the high
anisotropy of Co2? ions. The variation in saturation mag-
netization and coercivity for the investigated samples were
explained on the bases of exchange interactions. The
magnetic properties of the investigated samples changed at
low temperature (77 K) which were observed in shape of
the magnetic hysteresis M(H) loops as well as the coer-
civity and the squareness values. Co samples will be
hopeful for technological applications at or below room
temperature.
1 Introduction
Synthesis and application of magnetic nano particles with
sizes of a few nanometers is a subject of intense research
because of their interesting properties that make them
attractive, both from the scientific value of understanding
their properties, and the technological significance of
upgrading the performance of the existing materials [1, 2].
Nanoferrites attracted considerable interest for a number
of researchers, due to their promising technological
importance in a wide range of applications, including photo
catalysts [3, 4], magneto optical devices [5], high density
magnetic recording [6] and so on.
In the recent years, some researchers have investigated
the effect of rare earth ions [7], and different surfactant [8],
on the properties of nanoferrites. Generally, the physical
properties of ferrites are sensitive to the valence state and
distribution of cation over the tetrahedral (A-) and octa-
hedral (B-) sites of the spinel lattice. Therefore, the infor-
mation of cation distribution is essential to understand the
different physical properties of spinel ferrites [9].
Despite a large portion spinel ferrites are cubic, copper
ferrite (CuFe2O4) can have tetragonal unit-cell symmetry if
the sample is slowly cooled from high temperatures [10]. It
can be designated as a cubic close-packed arrangement of
oxygen ions with Cu2? and Fe3? ions at two different
crystallographic sites [11]. Copper is an inverse ferro-
magnetic spinel in which a small amount of Cu2? ions
migrate from octahedral B to tetrahedral A sites. On the
other hand the spinel cobalt ferrite has a cubic symmetry
and it has six crystallographic easy axes (directions) along
the cube edges of the crystal represented as \100[ and
four crystallographic hard axes (directions) across the body
diagonals denoted as \111[ [12–14]. CoFe2O4 shows
some excellent physical properties such as high coercivity,
chemical stabilities, moderate saturation magnetization,
low conductivity and good mechanical and large magnetic
anisotropy [15]. It is a hard magnetic material with a
magnetic ordering temperature around 520 �C [16].
The importance of spinel nano ferrite in many applica-
tions encourages us to through light on the properties of