Structural and Magnetic Properties of CoFe2O4 Thin Films via Sol-Gel Method

2014 ◽  
Vol 716-717 ◽  
pp. 159-162 ◽  
Author(s):  
Shao Hua Yang ◽  
Ding Guo Li ◽  
Hai Bin Yang ◽  
Hong Chun Yan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcined Temperature

Cobalt ferrite (CoFe2O4) thin films have been prepared on Si (001) substrates, with different calcined temperatures (Tcal=400°C~800°C). The films structure was studied by X-ray diffraction (XRD) and their surface was examined by scanning electron microscopy (SEM). The magnetic properties were measured with a vibrating sample magnetometer (VSM). For low calcined temperatures, the films presented a mixture of a CoFe2O4phase, with the cubic spinel structure, and cobalt and iron antiferromagnet oxides with CoO and FeO stoichiometries. As the calcined temperature increased, the CoO and FeO relative content strongly decreased, so that for Tcal=800°Cthe films were composed mainly by polycrystalline CoFe2O4. The magnetic hysteresis cycles measured in the films were horizontally shifted due to an exchange coupling field originated by the presence of the antiferromagnetic phases.

Structural and Magnetic Properties of CoFe2O4 / Si (001) Thin Films via Sol-Gel Method

2013 ◽  
Vol 744 ◽  
pp. 315-318
Author(s):  
Wei Rao ◽  
Ding Guo Li ◽  
Hong Chun Yan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcined Temperature

Cobalt ferrite (CoFe2O4) thin films have been prepared on Si (001) substrates, with different calcined temperatures (Tcal=400°C~800°C). The films structure was studied by X-ray diffraction (XRD) and their surface was examined by scanning electron microscopy (SEM). The magnetic properties were measured with a vibrating sample magnetometer (VSM). For low calcined temperatures, the films presented a mixture of a CoFe2O4phase, with the cubic spinel structure, and cobalt and iron antiferromagnet oxides with CoO and FeO stoichiometries. As the calcined temperature increased, the CoO and FeO relative content strongly decreased, so that for Tcal=800°Cthe films were composed mainly by polycrystalline CoFe2O4. The magnetic hysteresis cycles measured in the films were horizontally shifted due to an exchange coupling field originated by the presence of the antiferromagnetic phases.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Influence of Zinc-Zirconium Substitution on Magnetic Properties of Ba(ZnZr)xFe12-2xO19 Hexaferrite Prepared by the Molten Salt Method

2009 ◽  
Vol 79-82 ◽  
pp. 2071-2074 ◽  
Author(s):  
Hai Feng Li ◽  
Rong Zhou Gong ◽  
Xian Wang ◽  
Li Ren Fan ◽  
Gang He ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Molten Salt ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Chemical Compositions ◽  
Molten Salt Method ◽  
Vibrating Sample Magnetometer ◽  
Hexagonal Ferrites ◽  
X Ray Diffraction ◽  
X Ray

M-type hexaferrites Ba(ZnZr)xFe12-2xO19 (x=0, 0.5, 1.0, 1.5) powders, have been synthesized by molten salt method, where x varies from 0 to 1.5 in steps of 0.5. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer(VSM) were used to analyze the structures and magnetic properties. The results showed that, the magnetoplumbite structures for all samples calcining at 1100°C have been formed. The magnetic hysteresis loop measurements of the hexagonal ferrites powders showed that the saturation magnetization (Ms), the remanent magnetization (Mr), and the coercitivity (Hc) of ferrites depend strongly on the chemical compositions of materials. The data showed that the max Hc was obtained when substitution of x=1.0 (Hc=63.9 Oe), while the best Ms was obtained when substitution of x=0.5 (Ms=54.02 emu/g). Zn and Zr substitutions greatly modified the magnetic properties of BaM hexaferrite.

MAGNETIC PROPERTIES OF Co-FERRITE AND SiO2-DOPED Co-FERRITE THIN FILMS AND POWDERS BY SOL–GEL

2004 ◽  
Vol 03 (04n05) ◽  
pp. 463-470
Author(s):  
Y. C. WANG ◽  
J. DING ◽  
B. H. LIU ◽  
Y. SHI
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Magnetic Properties ◽  
Ferrite Thin Films ◽  
Scanning Electron

Thin films and powders of Co -ferrite and SiO 2-doped Co -ferrite were fabricated via the sol–gel method. The structural and magnetic properties of the films and powders were investigated with X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). VSM measurements showed an enhancement of coercivity by SiO 2-doping for Co -ferrite powders and thin films (coercivity of 3.5 kOe in SiO 2-doped thin films). XRD and SEM investigations revealed a nanostructure of the thin films. Low surface roughness was observed in our AFM study.

Study of the magnetic and structural properties of Al–Cr codoped Y-type hexaferrite prepared via sol–gel auto-combustion method

2015 ◽  
Vol 29 (14) ◽  
pp. 1550090 ◽  
Author(s):  
O. Mirzaee ◽  
R. Mohamady ◽  
A. Ghasemi ◽  
Y. Alizad Farzin
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Shape ◽  
Auto Combustion ◽  
Xrd Patterns ◽  
Cr Doping

Nanostructure of Y-type hexaferrite with composition of Sr 2 Ni 2 Al x/2 Cr x/2 Fe 12-x O 22 (where x are 0, 0.6, 1.2, 1.8, 2.4 and 3) were prepared by sol–gel auto-combustion method. The influence of Al and Cr doping on the structural and magnetic properties has been investigated. The X-ray diffraction (XRD) patterns confirm phase formation of Y-type hexaferrite. The microstructure and morphology of prepared samples were studied by high resolution field emission scanning electron microscope (FESEM) which shows the hexagonal shape for all of the samples. Magnetic properties were characterized using vibrating sample magnetometer (VSM). The magnetic results revealed that by increasing the Al and Cr to the structure, the coercivity was also increased from 840 Oe to 1160 Oe. Moreover it has been shown that with addition of dopants, saturation magnetization (Ms) and remnant magnetization (Mr) were decreased from 39.61 emu/g to 30.11 emu/g and from 17.51 emu/g to 14.62 emu/g, respectively, due to the entrance of nonmagnetic ions into Fe 3+ sites.

Sr1-xNdXFe12O19 Ferrite Synthesized through Sol-Gel Self-Combustion

2010 ◽  
Vol 146-147 ◽  
pp. 147-150 ◽  
Author(s):  
Zhan Yong Wang ◽  
Ming Lin Jin ◽  
Hui Chun Qian ◽  
Yong Zheng Fang ◽  
Jia Yue Xu
Keyword(s):  
Magnetic Properties ◽  
Citric Acid ◽  
Calcination Temperature ◽  
Differential Scanning Calorimeter ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
Doping Content ◽  
X Ray Diffraction ◽  
X Ray

Sr1-xNdxFe12O19 ferrites were Synthesized via sol–gel and self-combustion methods with Fe(NO3)3·9H2O，Sr(NO3)2 and citric acid. The as-synthesized powder was studied by differential scanning calorimeter (DSC). X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were applied to investigate the structure and magnetic properties. The powder was synthesized in different calcination temperature and doping content of Nd2O3. The experiment reveals that the magnetic properties of Nd3+ doped ferrites are less sensitive to calcination temperature comparing with no doping ferrites. The coercivity (Hcj) of Nd3+ doped ferrites reach 423.96 kA·m-1.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF BaFe12O19 THIN FILMS USING SUSPENSION OF NANO POWDERS

2012 ◽  
Vol 05 ◽  
pp. 760-764
Author(s):  
SAMAN SALEMIZADEH ◽  
S. A. SEYYED EBRAHIMI
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Barium Nitrate ◽  
Synthesis And Characterization ◽  
Vibrating Sample Magnetometer ◽  
Final Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Disperse Particles

BaM thin films have been synthesized by dispersing the dried gel nano powders prepared by Sol-Gel method. The solution was made by dissolving iron nitrate Fe ( NO 3).9 H 2 O , barium nitrate Ba ( NO 3)2 and citric acid in deyonized water and methanol. This sol was slowly evaporated until a dried gel was formed. This dried gel was then added to ethylene glycol. The final solution was vigorously shaken and mixed in ultrasonic cleaner for 30 min to disperse particles sufficiently. Then the prepared solution spin coated on Si (110) substrate. The obtained thin films were dried at 120 °C and then calcined at 900 °C for 1 h. The films were characterized using X-ray diffraction (XRD) and vibrating sample magnetometer (VSM).

Structural and Magnetic Properties of Ni0.5Zn0.5Fe2O4 Synthesized through the Sol-Gel Method

2014 ◽  
Vol 664 ◽  
pp. 75-79
Author(s):  
Beh Hoe Guan ◽  
Muhammad Hanif Zahari ◽  
Lee Kean Chuan
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Calcination Temperatures ◽  
Zn Ferrite

This study investigates the influence of calcination temperatures on the magnetic properties of Ni0.5Zn0.5Fe2O4(Ni-Zn) ferrites.Ni-Zn ferrite with the chemical formula Ni0.5Zn0.5Fe2O4was prepared from their respective nitrate salts through the sol-gel method. The resulting ferrites were characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). Single phased Ni0.5Zn0.5Fe2O4 was obtained at all calcination temperatures.FESEM Micrographs reveals an increase in the grain size with the increase of the calcination temperature. Consequently, the magnetic saturation of the samples were found to increase with each increase in the calcination temperature where the highest value obtained is 70.58 emu/g for the samples calcined at 1000°C.

Structural and Magnetic Properties of Nanogranular BaTiO3-CoFe2O4 Thin Films Deposited by Laser Ablation on Si/Pt Substrates

2008 ◽  
Vol 587-588 ◽  
pp. 303-307
Author(s):  
J.G. Barbosa ◽  
Bernardo G. Almeida ◽  
João P. Araújo ◽  
João Bessa Sousa ◽  
Jorge A. Mendes
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Magnetic Properties ◽  
Laser Ablation ◽  
Barium Titanate ◽  
Cobalt Ferrite ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Clear Trend ◽  
X Ray

Thin film nanocomposites of cobalt ferrite (CoFe2O4) dispersed in barium titanate (BaTiO3) matrix, have been deposited with different cobalt ferrite concentrations (from 20% to 70% CoFe2O4), as well as pure barium titanate and cobalt ferrite thin films (end members). The films were prepared by pulsed laser ablation on platinum covered Si(001) substrates. The films structure was studied by X-ray diffraction and their surface was examined by scanning electron microscopy (SEM). The magnetic properties were measured in a SQUID magnetometer. The results show that the deposited films are polycrystalline with a slight (111) barium titanate phase orientation and (311) CoFe2O4 phase orientation. The grain sizes measured from the X-ray diffraction peak widths, for both phases, are in the range 40nm to 100nm. However, as the concentration of the cobalt ferrite increases, the grain size of the BaTiO3 phase decreases, from 100nm to 30nm, up to 40% CoFe2O4 concentration beyond which the BaTiO3 grain size has an approximately constant value near 30nm. On the other hand the cobalt ferrite grain size does not show a clear trend with increasing cobalt ferrite concentration, fluctuating in the range 20nm to 30nm. The magnetic measurements show an increase of the magnetic moment from the low concentration region where the magnetic grains are more isolated and their magnetic interaction is small, towards the bulk value at higher CoFe2O4 concentrations. Also, a strong reduction of the magnetization with increasing temperature was observed, due to the corresponding decrease of the magnetocristalline anisotropy of the cobalt ferrite.

Strain Tuned Magnetic Properties of Epitaxial Cobalt Ferrite Thin Films

1999 ◽  
Vol 603 ◽  
Author(s):  
G. Hu ◽  
J.H. Choi ◽  
C.B. Eom ◽  
Y. Suzuki
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Cobalt Ferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ferrite Thin Films ◽  
Cation Redistribution ◽  
Structural Characterizations ◽  
Post Deposition

AbstractEpitaxial cobalt ferrite thin films have been fabricated on bare MgO substrates and compared to those grown on CoCr2O4 buffered MgAl2O4. Various structural characterizations, including x-ray diffraction, Rutherford backscattering spectroscopy and transmission electron microscopy, demonstrate excellent crystallinity of the films. Films grown under tension exhibit magnetic properties dominated by the stress anisotropy. In (110) oriented films grown on CoCr2O4 buffered MgAl2O4, post deposition annealing switched the in-plane easy and hard directions completely while no such behavior is observed in cobalt ferrite films grown on MgO. The anomalous behaviors observed in as-grown films and films after annealing can be explained in terms of lattice distortion and cation redistribution.

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