scholarly journals Effect of Al Doping on Magnetic Properties of Co-Mn Nanoferrites Synthesized via Citrate-Gel Method

2021 ◽  
Vol 33 (5) ◽  
pp. 1125-1132
Author(s):  
Shankar Barapati ◽  
M. Raghasudha ◽  
P. Veera Somaiah
Keyword(s):  
Magnetic Properties ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Aluminium Content ◽  
Energy Band Gap ◽  
Soft Magnetic ◽  
Chemical Route ◽  
Before And After ◽  
Uv Visible ◽  
Aluminium Doping

The structural and magnetic properties of aluminium substituted Co-Mn nanoferrites synthesized via a chemical route viz. citrate-gel autocombustion method have been reported. Aluminium content has been varied from x=0 to x=1 with an increment of 0.2 in Co0.75Mn0.25AlxFe2-xO4. The structural confirmation was done with the basic characterization techniques such as XRD study, FTIR spectroscopic and the surface morphology was examined using SEM and EDX spectroscopic analysis. To study the optical absorption behaviour of the prepared ferrites, UV-visible spectral analysis was carried out. XRD analysis established the formation of cubic spinel structure of the materials with the average crystallite size of 15.5 nm to 19.94 nm. FTIR spectra has shown two absorption peaks that are characteristic of spinel nano ferrites. From the UV-visible spectral data, energy band gap (Eg) values were evaluated. The data witnessed an increase in the Eg value of the ferrite by doping of Al3+ ion into the ferrite. Room temperature magnetization measurements were carried out before and after aluminium doping in the samples using vibrating sample magnetometer. It was revealed that the substitution of aluminium in the lattice has modified the material into a soft magnetic material. Consequently, they find applications in transformer and motor cores.

Structural, Optical, Ferroelectric and Magnetic Properties of NiTiO3 Ceramic Synthesized by Citrate Gel Method

2020 ◽  
pp. 2150004
Author(s):  
Pham Van Thang ◽  
Dang Duc Dung ◽  
Luong Huu Bac ◽  
Pham Phi Hung ◽  
Tran Vu Diem Ngoc
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Visible Spectrum ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Rhombohedral Crystal Structure ◽  
Hall Plot ◽  
Rhombohedral Crystal ◽  
Uv Visible

The NiTiO3 ceramic was synthesized in nanostructured form by citrate gel method. The phase structure, microstructure and magnetic properties of synthesized compounds were investigated by X-ray diffraction (XRD), scanning electron microscope and vibrating sample magnetometer. Williamson–Hall plot was used to calculate the crystallite size and microstrain of sample. The XRD analysis showed the formation of rhombohedral crystal structure of synthesized powders. The crystallite size is about 35[Formula: see text]nm and microstrain is [Formula: see text]. The optical band gap was estimated from UV-Visible spectrum with value of 2.43[Formula: see text]eV. The NiTiO3 samples showed coexistence of ferroelectric and antiferromagnetic properties at room temperature.

Microstructure and Magnetic Properties of CoFeHfO Rich Nanocrystalline Thin Films Application for High Frequency

2007 ◽  
Vol 558-559 ◽  
pp. 975-978
Author(s):  
L.V. Tho ◽  
K.E. Lee ◽  
Cheol Gi Kim ◽  
Chong Oh Kim ◽  
W.S. Cho
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Rf Sputtering ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Electrical And Magnetic Properties ◽  
Transmission Electron ◽  
Nanocrystalline Thin Films

Nanocrystalline CoFeHfO thin films have been fabricated by RF sputtering method. Co52Fe23Hf10O15 thin film is observed, exhibit good magnetic properties with magnetic coercivity (Hc) of 0.18 Oe; anisotropy fild (Hk) of 49 Oe; saturation magnetization (4лMs) of 21 kG, and electrical resistivity (ρ) of 300 01cm. The frequency response of permeability of the film is excellent. The effect of microstructure on the electrical and magnetic properties of thin film was studied using X-ray diffraction (XRD) analysis and conventional transmission electron microscopy (TEM). The results showed that excellent soft magnetic properties were associated with granular nannoscale grains of α-CoFe and α-Co(Fe) phases.

scholarly journals Investigating on Structural, Optical, Magnetic and Photocatalytic Activities of ZnS and Co2+: ZnS NPs Synthesized by Hydrothermal Process Under MeB Dye

2021 ◽  
Author(s):  
S. Upputuri ◽  
S. Lakshmanan ◽  
Ramalakshmi N ◽  
S. Arul Antony
Keyword(s):  
Room Temperature ◽  
Dopant Concentration ◽  
Hydrothermal Process ◽  
Average Crystallite Size ◽  
Band Gap Energy ◽  
Cubic Phase ◽  
Chemical Route ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Electron Trapping Center

Abstract In present work, the structural, morphological, optical and photocatalytic activities of ZnS and Co2+: ZnS NPs were prepared through chemical route as hydrothermal process at room temperature. ZnS and Co2+: ZnS were characterized by using various techniques such as, XRD, SEM-EDX, TEM-SAED, UV-visible, PL and BET. The spherical-like morphology with the average crystallite size was found to be 8 to 15 nm. Among them results, it showed that the Co2+ atoms were incorporated into the ZnS lattice, forming cubic phase as the Co2+ dopant concentration increases from 0 to 2 %. The band gap energy of the ZnS and Co2+: ZnS increases from 3.5 to 4.10 eV, which enables stronger absorption of UV region. During catalytic process, Co2+ act as electron trapping center, which inhibits the recombination of the photo induced holes and electrons as showed higher degradation efficiency for MeB.

scholarly journals Structural Optical Magnetic And Photocatalytic Properties of Ferromagnetic P-Type NiO: N-Type ZnO Nanocomposites

2021 ◽  
Author(s):  
G. Kavitha ◽  
K. Thanigai Arul ◽  
Manikandan Elayaperumal
Keyword(s):  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Ferromagnetic Behavior ◽  
Chemical Route ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Different Temperatures ◽  
Conducting Metal Oxides ◽  
P Type

Abstract The semiconductor-transition conducting metal oxides (p-type NiO: n-type ZnO) nanocomposites (NCs) called (NZO) are successfully prepared by a simple wet-chemical route followed by the systematic sintering at different temperatures such as 400°C, 500°C, 600°C, and 700 °C. The structure and morphology of the samples were characterized by X-ray diffraction (XRD), high-resolution scanning/transmission electron microscopy (HR-SEM/TEM), and energy-dispersive X-ray spectrometry (EDX) techniques. XRD analysis reveals that the average crystallite size of the NZO NCs was found to be in the range 16-18 nm. The synthesized sample discloses a ferromagnetic behavior. The photocatalytic degradation of rhodamine B in an aqueous solution was superior at the NZO NC at 600 °C in comparison with other samples. Here, the NZO NCs display to be good candidates for magnetic and photocatalytic application.

Microstructure and Magnetic Properties of Undercooled Fe-80at%Ni Alloys

2009 ◽  
Vol 620-622 ◽  
pp. 327-330
Author(s):  
Hui Xie ◽  
G.H. Bai ◽  
L. Jia ◽  
E.K. Liu ◽  
Zhen Lin Lu
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Grain Coarsening ◽  
Ni Alloys ◽  
Purification Technique ◽  
Maximum Undercooling

Bulk Fe-80at%Ni melts were undercooled by using cyclic superheating and glass slag purification technique, and the maximum undercooling 340 K could be achieved. The microstructures of Fe-80at%Ni alloys were observed by means of optical microscope (OM). The phase composition was identified by X-ray diffraction (XRD) analysis. The magnetic properties of Fe-80at%Ni alloys were measured by vibrating sample magnetometer (VSM) with a DC M-H analyzer. The results showed that there was only single γ-(Fe, Ni) phase existing in undercooled Fe-80at%Ni alloys. Two grain refinements and one grain coarsening were observed in the undercooling range from 28 K to 340 K. The first grain refinement could be ascribed to dendrite-remelting, and the second to recrystallization induced by the stress originating from rapid solidification. The grain coarsening could be considered as a result of solid-state grain coalescence. The measurement of soft magnetic properties showed that the grain size D decreases with an increase of undercooling, the maximum Ms is 109.98emu/g, corresponding to minimum grain size 42.9μm or undercooling 210 K, and the coercive force Hc is in proportion to the reciprocal of grain size D-1.

Magnetic Evaluation of Ni-Zn Ferrites Doped with Aluminium

2012 ◽  
Vol 727-728 ◽  
pp. 528-532 ◽  
Author(s):  
P.T.A. Santos ◽  
Daniel Cornejo ◽  
P.T.A. Santos ◽  
Hélio Lucena Lira ◽  
Ana Cristina Figueiredo de Melo Costa
Keyword(s):  
Saturation Magnetization ◽  
Coercive Field ◽  
Magnetic Behavior ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Reaction Method ◽  
X Ray ◽  
Zn Ferrite ◽  
Before And After

Ni0.5Zn0.5Fe1.97Al0.3O4ferrites were synthesized by combustion reaction method and after calcined at 700°C/1 h, with the aim to investigate how the Al3+ions substitution byNi2+ions can influence the magnetic properties. The results from X-ray diffraction showed the formation of a unique Ni-Zn ferrite phase with average crystallite size of 8 and 22nm, before and after calcination, respectively. The synthesize samples presented a superparamagnetic behavior, with saturation magnetization of 0.9 emu/g, and coercive field of 0.05 kOe, and after calcination the samples presented soft magnetic behavior with saturation magnetization of 40.0 emu/g and coercive field of 0.04 kOe.

Magnetic Properties of Nanocomposites Metal-Carbon

2015 ◽  
Vol 233-234 ◽  
pp. 538-541
Author(s):  
Alexander Aleshnikov ◽  
Haider S. Mohammed Al-Azzawi ◽  
Y. Kalinin ◽  
Alexander Sitnikov ◽  
Oksana Tarasova
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Ion Beam ◽  
Heterogeneous Systems ◽  
Soft Magnetic Properties ◽  
Ion Beam Sputtering ◽  
Ferromagnetic Alloy ◽  
Soft Magnetic ◽  
Before And After ◽  
Beam Sputtering

The films of heterogeneous systems based on ferromagnetic alloy and С were obtained by ion-beam sputtering. The concentration dependence of the resistance of composites was measured before and after heat treatment. The research of magnetostatic and magnetodynamic properties of heterogeneous metal-carbon showed that compounds (Co)Х(C)100-Х (Co40Fe40B20)Х(С)100-Х (Co45Fe45Zr10)Х(C)100-Х after the percolation threshold have good soft magnetic properties.

Magneto-transport and Magnetic Properties of Fe Doped Nanometric Polycrystalline La0.7Sr0.3MnO3 CMR Manganites

2009 ◽  
Vol 1183 ◽  
Author(s):  
Sanjoy Paul ◽  
Tapan K. Nath
Keyword(s):  
Magnetic Properties ◽  
Transport Properties ◽  
Lattice Structure ◽  
Double Exchange ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Chemical Route ◽  
Selected Area Electron Diffraction ◽  
Xrd Patterns ◽  
20 Nm

AbstractWe have investigated the effect of 3d-transition metal Fe (Iron) doping at Mn site of nanometric polycrystalline La0.7Sr0.3MnO3 (i.e. La0.7Sr0.3Mn1-xFexO3; 0 ≤ x ≤ 0.1) CMR manganites on magneto-transport and magnetic properties. Nanocrystalline Fe doped La0.7Sr0.3MnO3 powders were synthesized through chemical route “Pyrophoric Reaction Process” and calcinated at 850°C for 5 hrs. X-ray diffraction (XRD) patterns of synthesized powder indicate that all samples are having perovskite structure without any secondary impurity phase. Average crystallite size was found to be 20 nm using Debye Scherer formula. Transmission electron micrographs (TEM) show that the average particle sizes are in nanometric regime (φ ˜ 50 nm) and samples are polycrystalline in nature which was observed through selected area electron diffraction (SEAD) patterns. The effect of Fe doping at Mn site of La0.7Sr0.3MnO3 was found to change substantially the magnetic and transport properties without modifying lattice structure. The suppression of magnetic and transport properties were observed due to dilution of double exchange mechanism in Mn3+- O2--Mn4+ network in La0.7Sr0.3MnO3.

SYNTHESIS AND CHARACTERIZATION OF Al DOPED ZnO NANOPARTICLES

2013 ◽  
Vol 22 ◽  
pp. 630-636 ◽  
Author(s):  
WASI KHAN ◽  
Z. A. KHAN ◽  
A. A. SAAD ◽  
S. SHERVANI ◽  
A. SALEEM ◽  
...  
Keyword(s):  
Energy Gap ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Uv Visible ◽  
Doped Zno

Undoped and Al-doped ZnO (AZO) nanoparticles (NPs) have been successfully synthesized by the simple sol-gel method. The NPs have been characterized by a number of techniques as x-ray diffraction (XRD), UV-visible spectroscopy and scanning electron microscopy (SEM) at room temperature for 0%, 0.5%, 1% and 2% of Al concentration. The structural characteristics were examined using XRD and SEM with EDS. XRD analysis reveals that all samples crystallizes in polycrystalline nature with wurtzite lattice and exhibit no other impurity phase. The average crystallite size decreases with increase in Al concentration. The absorption spectra indicate increase in optical energy gap (Eg) with increase in Al ion doped into the ZnO lattice site.

Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

1988 ◽  
Vol 46 ◽  
pp. 770-771
Author(s):  
June D. Kim
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Ternary Phase Diagram ◽  
Vertical Tube ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Soft Magnetic ◽  
Quenching Temperature ◽  
Thin Foils ◽  
Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

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