scholarly journals Microstructural and Mössbauer Spectroscopy Studies ofMg1-x ZnxFe2O4x=0.5,0.7Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Jinpei Lin ◽  
Yun He ◽  
Qing Lin ◽  
Ruijun Wang ◽  
Henian Chen
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Zinc Concentration ◽  
Magnetic Phase ◽  
Sol Gel ◽  
Paramagnetic Behavior ◽  
Different Temperatures ◽  
Phase Spinel ◽  
Spectroscopy Studies ◽  
Xrd Patterns

Zinc substituted magnesium ferriteMg1-xZnxFe2O4(x=0.5,0.7)powders have been prepared by a sol-gel autocombustion method. XRD patterns show that the specimens withx=0.5and 0.7 exhibit single-phase spinel structure, and more content of Zn in specimens is favorable for the synthesis of pure Mg-Zn ferrites. Room temperature Mössbauer spectra ofMg1-xZnxFe2O4annealed at 800°C display transition from ferrimagnetic behavior to super paramagnetic behavior with increase in zinc concentration. The Mössbauer spectras of Mg0.5Zn0.5Fe2O4annealed at different temperatures display the magnetic phase change of the ferrite particles.

Co-Ferrite (CoFe2O4): A Material with High Magnetostriction Produced by Sol-Gel Method

2011 ◽  
Vol 326 ◽  
pp. 157-164
Author(s):  
Nasir Mehmood ◽  
Roland Grössinger ◽  
Rieko Sato Turtelli ◽  
Muhammad Aamir Raza ◽  
Sohail Afzal Khan ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Single Phase ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Xrd Pattern ◽  
Gel Method ◽  
Heat Treated ◽  
Different Temperatures ◽  
Phase Spinel

Polycrystalline Co-ferrite was produced by modified citrate gel method. Samples were afterward heat treated at different temperatures upto 1300°C. The XRD pattern shows that all samples exhibit a single phase spinel structure and improvement and sharpness in intensity of peaks with increasing annealing temperature. Measurement of hysteresis loops demonstrate that after the heat treatment a saturation magnetization of 60- 84 emu/gis obtained. Measurements of the longitudinal magnetostriction gave values between 20 ppm and 130 ppm. Magnetostriction increases gradually with increase in annealing temperature and becomes highest when the saturation magnetization values are larger.

Proficient Ni-Zn-Cr Ferrites: Synthesis and Characterization

2012 ◽  
Vol 510-511 ◽  
pp. 343-347
Author(s):  
S. Nasir ◽  
M.A. Malik ◽  
G. Asghar ◽  
G.H. Tariq ◽  
M. Akram ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zn Ferrite ◽  
Phase Spinel ◽  
Scherrer Formula ◽  
Xrd Patterns ◽  
Cr Doping

Ni-Zn ferrite nanoparticles with Cr doping, having the general formula Ni0.5Zn0.5CrxFe2-xO4(x = 0.1, 0.3, 0.5) were prepared by simplified sol-gel method and sintered at 750±5°C. The structural and magnetic properties of the samples sintered at 750±5°C were studied. From X-ray diffraction (XRD) patterns, it was confirmed that the samples have single phase spinel structure. The crystallite size was calculated from the most intense peak (3 1 1) using the Debye Scherrer formula and was found to be in the range of 29-34 nm. The scanning electron microscope images showed that the particle size of the samples were in the range 60-120nm. Quantum design PPMS model 6700 was used to study magnetic properties of these samples. The effect of Cr doping on the magnetic properties was explained on the basis of cations distribution in the crystal structure.

Synthesis and Properties of Lead Free Ferroelectric Na0.5Bi0.5TiO3 Ceramic at Different Sintering Temperature

2015 ◽  
Vol 830-831 ◽  
pp. 620-623 ◽  
Author(s):  
Kusum Parmar ◽  
Hakikat Sharma ◽  
Sarita Sharma ◽  
N.S. Negi
Keyword(s):  
Phase Transition ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Free ◽  
Characteristic Absorption Band ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Rhombohedral Symmetry

Lead Free Ferroelectric Na0.5Bi0.5TiO3 (NBT) Ceramic has been synthesized using sol gel method. The prepared NBT samples have been sintered at different temperatures 850°C, 950°C, 1050°C and 1150°C to achieve best sintering temperature. Structural analyses have been carried out using XRD and FTIR measurements. XRD patterns confirm perovskite structure having rhombohedral symmetry for all samples which is also supported by characteristic absorption band at ~627cm-1 in FTIR spectra. Dielectric properties of NBT samples with frequency and temperature have been studied. NBT sample sintered at 1050°C exhibit comparatively high value of dielectric constant (ε’) and phase transition temperature (Tm). Ferroelectric properties of NBT samples have been studied at room temperature. Comparatively, better ferroelectric properties are observed for NBT sample having remnant polarization (Pr)~ 14.7 μC/cm2and coercive field (Ec)~ 26.8 kV/cm sintered at 1050°C.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

High Temperature Properties of CoFe/CoNi and Fe/CoNi Biphase Microwires

2015 ◽  
Vol 233-234 ◽  
pp. 265-268 ◽  
Author(s):  
Irene Iglesias ◽  
Rhimou El Kammouni ◽  
Kseniay Chichay ◽  
Manuel Vazquez ◽  
Valeria Rodionova
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Amorphous Structure ◽  
Magnetic Behaviour ◽  
Heating Process ◽  
Saturation Magnetostriction ◽  
Magnetostriction Constant ◽  
Different Temperatures ◽  
Drawing Technique

The objective of this work has been to analyze the high-temperature behavior of magnetically single-and biphase microwires because of its interest from fundamental and applications viewpoints. Two alloy compositions with amorphous structure covered by glass have been prepared as magnetically single phase microwires by quenching & drawing technique: CoFe-based with near zero saturation magnetostriction constant and Fe-based with positive saturation magnetostriction constant. The same wires were used as the core for magnetically biphase microwires. Second CoNi phase was deposited by electroplating. Magnitudes as saturation magnetization and hysteresis parameters are determined in the temperature range from room temperature up to 1200 K. We proceed to a comparative analysis of their magnetic behaviour at different temperatures as well as after cooling down to room temperature. Information on the Curie temperature of different phases and on the influence of heating process on the magnetic properties is thus derived.

Structural, magnetic and high frequency (1–6 GHz) parameters of Sr-substituted BaFe2O4 monoferrites synthesized by sol–gel method

2019 ◽  
Vol 33 (19) ◽  
pp. 1950219 ◽  
Author(s):  
Mukhtar Ahmad ◽  
Jawaria Shaheen ◽  
Waseem Abbas Hashmi ◽  
Majid Niaz Akhtar ◽  
Muhammad Asif
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Anisotropy Constant ◽  
Dielectric Parameters ◽  
Single Phase Sample ◽  
Heat Treated Sample ◽  
Auto Combustion ◽  
Phase Spinel

In this work, Sr-substituted samples of single-phase spinel monoferrites with chemical formula [Formula: see text] (x = 0.00, 0.33, 0.67, 1.00) were synthesized using sol–gel auto-combustion method. In order to confirm the single-phase formation of these samples, a sample (x = 0.00) was chosen for heat treatment at different temperatures (100, 300, 400, 600 and [Formula: see text]) for 4 h. The heat treated sample was then investigated by X-ray diffraction (XRD) analysis and results showed that a single-phase sample can be successfully synthesized at a temperature of [Formula: see text], which is much lower than that reported in earlier literature for synthesis of same structured samples. All the synthesized samples were then sintered at [Formula: see text] for 4 h to achieve better crystallinity. From XRD patterns, lattice parameters, cell volume and XRD density as a function of Sr-substitution were calculated. Scanning electron microscopy (SEM) results showed that the grain size increased as the temperature was increased. Fourier transform infrared spectroscopy (FTIR) results confirmed the single-phase spinel monoferrites at [Formula: see text]. From M–H loops (x = 0.0, 0.33, 0.67 and 1.00), different magnetic parameters such as saturation magnetization [Formula: see text], remanance [Formula: see text], coercivity [Formula: see text] and magnetic moment [Formula: see text] were calculated. Magnetocrystalline anisotropy constant and Y–K angles of Sr-doped Ba monoferrites were also calculated. In addition, the variation of different dielectric parameters (real permittivity, imaginary permittivity, real permeability, imaginary permeability, ac conductivity and loss tangent) as a function of frequency (1–6 GHz) has been discussed in this work. The results suggest that the synthesized materials have many advantages over previously reported single-phase spinel monoferrites.

Effect of Annealing Atmosphere on the Morphology of Copper Oxide Thin Films Deposited on TiO2 Substrates Prepared by Sol-Gel Process

2013 ◽  
Vol 594-595 ◽  
pp. 113-117 ◽  
Author(s):  
Dewi Suriyani Che Halin ◽  
Ibrahim Abu Talib ◽  
Abdul Razak Daud ◽  
Muhammad Azmi Abdul Hamid
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Copper Oxide ◽  
Spin Coating ◽  
Sol Gel ◽  
Annealing Atmosphere ◽  
Oxide Thin Films ◽  
Different Temperatures ◽  
Xrd Patterns

Copper oxide films were prepared via sol-gel like spin coating starting from methanolic solutions of cupric chloride onto the TiO2 substrates. Films were obtained by spin coating under room conditions (temperature, 25-30 °C) and were subsequently annealed at different temperatures (200-400 °C) in oxidizing (air) and inert (N2) atmospheres. X-ray diffraction (XRD) patterns showed crystalline phases, which were observed as a function of the annealing conditions. The film composition resulted single or multi-phasic depending on both temperature and atmosphere. The grain size of film was measured using scanning electron microscopy (SEM) and the surface roughness of thin films was characterized by atomic force microscopy (AFM). The grain size of which was annealed in air at 300 °C was 30.39 nm with the surface roughness of 96.16 nm. The effects of annealing atmosphere on the structure and morphology of copper oxide thin films are reported.

INFLUENCE OF SAMARIUM SUBSTITUTION ON IMPEDANCE DIELECTRIC AND ELECTROMECHANICAL PROPERTIES OF Pb(1-x)K2xNb2O6

2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Electromechanical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis

Ferroelectric, hysteresis, impedance spectroscopy parameters, AC conductivity, and piezoelectric properties in the ceramics of Pb 0.74 K 0.52 Nb 2 O 6 and Pb 0.74 K 0.13 Sm 0.13 Nb 2 O 6 have been studied. X-ray diffraction study reveals single phase with the orthorhombic structure. The samples were characterized for ferroelectric and impedance spectroscopy properties from room temperature to 600°C. Cole–Cole plots (Z″ versus Z′) are drawn at different temperatures. The results obtained are analyzed to understand the conductivity mechanism in both the samples. The piezoelectric constant d33 has been found to be 96 × 10-12 C/N in PKN.

Structural and Ferromagnetic Properties of Ho-Doped BiFeO3 Films

2017 ◽  
Vol 727 ◽  
pp. 996-1000 ◽  
Author(s):  
Ning An ◽  
Hai Tao Zhang ◽  
Cheng Zhi Liu ◽  
Cun Bo Fan ◽  
Xue Dong ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Raman Spectroscopy ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Wave Number ◽  
Ferromagnetic Property ◽  
Peak Intensity ◽  
Structure Morphology ◽  
Xrd Patterns

In order to improve the structural and ferromagnetic property of BiFeO3, the effects of Ho3+ doping is systematically investigated. Pure BiFeO3 and Ho-doped BiFeO3 thin films are fabricated by sol-gel method, and the phase structure, morphology, crystalline structure, ferromagnetic are characterized by XRD, SEM, Raman spectra and VSM, respectively. The XRD patterns of the samples indicate that all the compounds crystallize in rhombohedral distorted perovskite structure with space group R3c and the Ho substitution can suppress the intrinsic formation of the miscellaneous phase. The SEM proves that along with the increasing of Ho concentration, the surface roughness of BiFeO3 is decreased due to the reduction of defects in the preparation. From the Raman spectroscopy, it is found that the peak intensity of 8 modes in Bi1-xHoxFeO3 are increased and the modes shift to higher wave number. Besides, the VSM results show that the ferromagnetic of the samples is enhanced with increasing of Ho concentration. When x=0.1, Ms is improved to be 4.8emu/g. The results can prove that the Ho3+ doping can reduce the volatilization of Bi3+, decrease the concentration of oxygen vacancies and improve the room-temperature ferromagnetic of BiFeO3.

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