scholarly journals Resistivity Enhancement of Sr-Hexaferrite Using Rare Earth Dopant to Minimize Energy Losses

2018 ◽  
Vol 778 ◽  
pp. 195-199 ◽  
Author(s):  
Nahall Niazi ◽  
Omer Farooq ◽  
Fatima Tuz Zahra ◽  
Muhammad Anis-ur-Rehman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Strontium Hexaferrite ◽  
Energy Losses ◽  
X Ray Diffraction ◽  
High Frequencies ◽  
X Ray ◽  
Co Precipitation

Strontium hexaferrite is a material of choice due its various magnetic applications. Energy losses are a prominent issue in these magnetic materials. To lower these energy losses, we need to improve the resistivity by reducing eddy current losses. In this work nanoparticles of Gadolinium (Gd) doped Sr-hexaferrite (SrFe12-xGdxO19 x =0 .0, 0.1) have been synthesized by co-precipitation method. Structural analysis was done by using X-ray diffraction technique (XRD). It was found that the formation of single phase i.e. hexagonal structure has been achieved when the samples were sintered at 920°C for 20 minutes. AC electrical properties such as conductivity (𝜎ac), dielectric constant (ε′), dielectric loss (tanδ) and impedance (Z); real (Z') and imaginary (Z") parts have been studied as a function of frequency at room temperature. Aim of the work was to enhance the resistivity and was successfully achieved. Gd doped sample is proposed as an energy efficient material to be used in devices working at high frequencies.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

Preparation and Characterization of Ag and Co Doped ZnO Nano Particles

2012 ◽  
Vol 584 ◽  
pp. 248-252
Author(s):  
B. Sankara Reddy ◽  
S. Venkatramana Reddy ◽  
R.P. Vijaya Lakshmi ◽  
N. Koteeswara Reddy
Keyword(s):  
Blue Emission ◽  
Photo Luminescence ◽  
Hexagonal Structure ◽  
Nano Particles ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation ◽  
Co Doped

Pure ZnO and Ag, Co doped ZnO nano particles [Zn1-xAgxCoyO, where x = 0.00 and 0.05, y = 0.05] were synthesized by chemical co precipitation method without use of surfactant. All the prepared samples calcinated in 1 hour at 500oC, after that the morphology of the samples were evaluated by Scanning Electron Microscope (SEM). The X- ray diffraction (XRD) results indicated that the synthesized co-doped ZnO nano crystals had the pure hexagonal structure without any significant change in the structure affected by Ag and Co substitution. Dopant elements Ag and Co are present in the ZnO host material and conformed by Energy Dispersive Analysis of X-ray Spectra (EDAX). The incorporation of Ag+ in the place of Zn2+ has made a considerable decrease in the size of nano crystals as compared to pure ZnO nano particles (It is to be noted that Co should be kept constant at 5 mol %). Blue emission was observed by Photo Luminescence (PL) Spectra.

Synthesis and Gas Sensing Properties of SnO2-CuO Nanocomposites

2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.

scholarly journals A Study of Photocatalytic Degradation of Betalain Pigment from Kitchen Waste, Semiconductive Nanostructured TiO2 Used as a Photocatalyst

2018 ◽  
Vol 15 (3) ◽  
pp. 272-278
Author(s):  
G. Muthukumar ◽  
B Arjunkumar ◽  
R. Vignesh ◽  
G. Ramalingam
Keyword(s):  
Beta Vulgaris ◽  
Room Temperature ◽  
Precipitation Method ◽  
Polluted Water ◽  
Tio2 Powder ◽  
X Ray Diffraction ◽  
Kitchen Waste ◽  
X Ray ◽  
Co Precipitation ◽  
Betalain Pigment

Well crystallinenanostructured TiO2 powder was synthesised by Co-precipitation method using Titanium (IV) isopropoxide and CTAB are precursor materialsto maintain in 1:1 ratio concentration. The synthesised power was structurally, morphologically and optically analysed to using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and UV-Vis absorption spectra. The betalain pigment of polluted water was prepared from Beta vulgaris extract at room temperature (RT). The 89% of betalain pigment was degraded at 40 min from Beta vulgaris extract polluted water using as-prepared TiO2 powder as a photocatalystmaterial under visible light.

Removal of Formaldehyde Using Mn-Ce-Fe Oxide Catalyst

2013 ◽  
Vol 634-638 ◽  
pp. 567-570
Author(s):  
Hai Zhao ◽  
Ke Jian Han ◽  
Yao Tong ◽  
Xiao Qi Sha ◽  
Yang Yang Li
Keyword(s):  
Room Temperature ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Fe Oxide ◽  
X Ray ◽  
Surface Areas ◽  
Transmission Electron ◽  
Co Precipitation

Mn-Ce-Fe Oxide catalysts were prepared by a co-precipitation method using precipitants NH4OH. The catalysts were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and sSubscript textuperior catalytic performance at room temperature. The catalysts would reduce substantially indoor formaldehyde concentrations in the present of airstreams.

Microstructures, Electrical and Magnetic Properties of Zn Doped Co Nanoferrites

2012 ◽  
Vol 510-511 ◽  
pp. 221-226 ◽  
Author(s):  
M. Akram ◽  
M. Anis-ur-Rehman ◽  
M. Mubeen ◽  
M. Ali
Keyword(s):  
Magnetic Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Crystallite Sizes ◽  
Co Precipitation

Non toxicity, bio compatibility and nanometer sizes regime which is comparable to the size of a cell, makes nanocrystalline Co ferrites particles very proficient. In the present research Zn doped cobalt ferrites were prepared by the chemical co-precipitation method and characterized by X-ray diffraction (XRD) at room temperature for structural analysis. X-ray diffraction patterns confirmed the FCC spinel structure of synthesized particles. Crystallite sizes were calculated from the most intense peak (311) using the Debye-Scherrer formula. The obtained crystallite sizes were in nanometer range for all the samples synthesized at reaction temperature of 70°C. Then samples were sintered at 550°C for 2 hours, characterized again by X-ray diffraction at room temperature. The crystallite sizes and lattice constants for all the samples were calculated again from the data obtained by XRD. DC electrical resistivity and AC electrical transport properties were analyzed. The magnetic properties such as coercivity (Hc) and remanence (Mr) of Co1-xZnxFe2O4for x = 0.0, 0.2, 0.4 were measured at room temperature by vibrating sample magnetometer. Coercivity and remanence were found maximum with minimum value of Zn in Co1-xZnxFe2O4.Observed structural and conduction properties of synthesized nanomaterials were correlated.

Synthesis of LiFePO4 Cathode Materials by a Chemical Method

2011 ◽  
Vol 675-677 ◽  
pp. 57-60
Author(s):  
Yuan Sun ◽  
Xiu Juan Zhao ◽  
Rui Ming Ren
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Method ◽  
Single Phase ◽  
Raw Materials ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Scanning Electron

The olivine-type LiFePO4 powder was prepared by a chemical method using the synthesized FePO4⋅2H2O, LiOH and glucose as raw materials. The synthesized FePO4⋅2H2O powder was obtained by co-precipitation method. FePO4⋅2H2O and LiFePO4 powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed the synthesized FePO4⋅2H2O powder at pH of 2.05 was in a single phase and nearly spherical in shape. Using the synthesized powders to prepared LiFePO4 at 600 °C in vacuum for 2 h was nearly spherical in shape and whose size was in the range of 0.1-0.5μm.

STRUCTURE, MORPHOLOGICAL, MAGNETIC AND OPTICAL PROPERTIES OF CuxMg1-xFe2O4 (x = 0, 0.5, 1) NANO FERRITES SYNTHESIZED BY CO-PRECIPITATION METHOD

2021 ◽  
pp. 46-54
Author(s):  
Chinh
Keyword(s):  
Saturation Magnetization ◽  
Spinel Structure ◽  
Single Phase ◽  
Secondary Phase ◽  
Ferromagnetic Material ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Patterns ◽  
Co Precipitation

CuxMg1.xFe2O4 nanoparticles were successfully synthesized by co-precipitation. The samples were calcined at 900 oC for 3 h and X-ray diffraction analysis showed that Cu0.5Mg0.5Fe2O4 had a single phase cubic spinel structure, while formation of secondary phase of Fe2O3 was observed in XRD patterns of CuFe2O4, MgFe2O4. The saturation magnetization (Ms) of Cu0.5Mg0.5Fe2O4 is in between the saturation magnetization values of CuFe2O4 and MgFe2O4 nanoparticles, CuFe2O4 is a ferromagnetic material, while MgFe2O4 and Cu0.5Mg0.5Fe2O4 show superparamagnetic behavior. The synthesized spinel ferrites were fully characterized using scanning electron microscopy (SEM), FTIR spectroscopy, energy dispersive spectroscopy (EDS) and UV-vis spectrophotometry.

MICROSTRUCTURE AND MAGNETIC PROPERTIES CHANGE OF Fe3O4 NANOPARTICLES SYNTHESIZED UNDER MAGNETIC FIELDS AT ROOM TEMPERATURE

2009 ◽  
Vol 23 (23) ◽  
pp. 2723-2731 ◽  
Author(s):  
JUN WANG ◽  
SIHUA XIA ◽  
SHIHE CAO
Keyword(s):  
Magnetic Properties ◽  
Magnetic Fields ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Promising Technique ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Microstructure And Magnetic Properties

Magnetite nanoparticles have been synthesized by a co-precipitation method under magnetic fields (0~1 T) at room temperature. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and their microstructure analysis were evaluated on a Mössbauer spectrum. It was found that the Fe 3 O 4 samples produced under a magnetic field of 1 T had a much higher saturation magnetization (15.3 emu/g) than those produced under 0.6 T (7.56 emu/g) and 0 T magnetic fields (6.59 emu/g). This interesting result implies that magnetic fields can affect the growth of Fe 3 O 4 nanoparticles and further change the microstructure and crystallinity of Fe 3 O 4 nanoparticles. It is expected that this process could also be a promising technique to improve the magnetic properties of other magnetic materials.

scholarly journals Thermoluminescence of Undoped and Cu Doped CdS Nanoparticles

2019 ◽  
Vol 9 (1) ◽  
pp. 166-169
Keyword(s):  
Room Temperature ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Particle Sizes ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Co Precipitation

In this paper an attempt has been made to synthesize undoped and 1wt% Cu doped CdS nanoparticles through chemical co-precipitation method. Prepared particles were characterized to explore their structural and thermoluminescence properties. The X-ray diffraction analysis reveals a hexagonal crystal structure at room temperature. The particle sizes are determined by Scherer formula for both undoped and doped CdS nanoparticles of various concentrations. The average grain size of undoped and Cu doped nanoparticles is found to be 32.81nm and 22.3nm respectively. The thermoluminescence studies of these above samples show TL peaks occurring at temperatures 379,428,471,510 and 550 Kelvin corresponding to activation energy 0.7 eV, 0.9eV, 1.2 eV, 1.4 eV and 1.3eV respectively.

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