scholarly journals Effect of pH Value on Synthesis and Properties of Zinc Cobalt Ferrite Nano Powders Prepared via Co-Precipitation Method

2020 ◽  
Author(s):  
Behrooz Shahbahrami ◽  
Sayed Mahmood Rabiee ◽  
Reza Shidpoor
Keyword(s):  
Tensile Strain ◽  
Cobalt Ferrite ◽  
Ph Value ◽  
Raw Materials ◽  
Compressive Strain ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Effect Of Ph ◽  
Co Precipitation ◽  
Crystallite Diameter

Abstract The effect of pH value on the synthesis of zinc cobalt ferrite nano powder via co-precipitation method was investigated. Zinc cobalt ferrite (Co0.6Zn0.4Fe2O4) precipitated using a solution of nitrate raw materials under different pHs (pH=8, 10, 11, 12 and 14) and calcined at 750 °C for 2 hours. The obtained nano-powders were characterized by X-ray diffraction (XRD), Williamson-Hall relations and Extrapolate functions, field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) measurements. The amount of pH had a significant effect on the structural and magnetic properties of the synthesized powders. At pHs 8 and 10, a tensile strain and above that a compressive strain was created in the system. By changing the tensile strain to compression the crystallite diameter increased, so that the crystallite diameter increased from 19.3 nm at pH 8 to 47.8 nm for pH =11. The HC of the all samples was in the range of 140-150 Oe. The saturation magnetization, anisotropy and Bohr magneton constants were 100.38 emu/gr, 15357.70 erg/Oe and 4.27, respectively for the synthesized sample at pH=11, which were higher than the other samples. These changes are due to the effect that pH has on the parameters of the crystallite diameter, particle size and also on the cation distribution of the ions in tetrahedral/octahedral spaces.

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.

Synthesis Conditions of Nano-Hydroxyapatite Using Chondroitin Sulfate by Co-Precipitation Method

2011 ◽  
Vol 236-238 ◽  
pp. 2076-2079
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Yong Huang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Chondroitin Sulfate ◽  
Ph Value ◽  
Orthogonal Design ◽  
Precipitation Method ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Co Precipitation

The introduction of biomineralization was coupled with the co-precipitation synthesis process of nano-hydroxyapatite with the addition of chondroitin sulfate as a template agent. The effect of a variety of processing conditions on the properties of final hydroxyapatite (HA) product was investigated by orthogonal design. The ratio of calcium to phosphorus was detected by chemical analysis, the phase composition was evaluated by X-ray diffraction (XRD), and the powder morphology was characterized by transmission electron microscope (TEM). The process scheme, moreover, was optimized by the analysis of four aspects which may have different extent of influence on product properties. It can be concluded from the results that product properties can be affected remarkably by the content of chondroitin sulfate and the pH value of reactant, less remarkably by the reaction temperature and slightly by the reaction time.

Technological Conditions and Magnetic Properties of Y-Type Hexaferrite Prepared by Chemical Co-Precipitation Method

2011 ◽  
Vol 412 ◽  
pp. 146-149
Author(s):  
Wen Guo Chen ◽  
Jian Qing Dai ◽  
Jing Bing Xia ◽  
Yao Min Ding ◽  
Zhi Gang Hu
Keyword(s):  
Magnetic Properties ◽  
Ph Value ◽  
Initial Permeability ◽  
Precipitation Method ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Specific Saturation Magnetization ◽  
Particle Size Analyzer ◽  
Co Precipitation

The Y-type hexaferrite precursors was synthesized by co-precipitation, and the pivotal technological conditions, including pH value, temperature (T), rotate speed (R) and the flow velocity of salt solution (V) were discussed. The particles of precursors were studied by Laser particle size analyzer (LPS). The precursor calcined at 900°C was characterized via X-ray Diffraction (XRD), the vibrating sample magnetometer (VSM) and HP4291A impedance analyzer were used to investigated magnetic properties. The results showed that the particle sizes were around 3µm (D50) and the distribution range was from 2.28μm to 4.47μm, in the optimized technological conditions: pH = 10.50, T = 50°C, R = 300 rpm, V = 0.35 ml/min, SDBS = 0.3 g/L, the specific saturation magnetization, coercive force, residual magnetization, initial permeability and factor of quality of the sample were σs≈ 29.72A·m2·kg-1, Hc≈ 4.11/kA·m-1, σr≈ 7.74 A·m2·kg-1, μi≈ 9 and Q ≈ 18 respectively.

Synthesis of LiFePO4 Cathode Materials by a Chemical Method

2011 ◽  
Vol 197-198 ◽  
pp. 1049-1052
Author(s):  
Yuan Sun ◽  
Xiu Juan Zhao ◽  
Guo Jun Li ◽  
Rui Ming Ren
Keyword(s):  
Chemical Method ◽  
Single Phase ◽  
Raw Materials ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Co Precipitation

The olivine-type LiFePO4powder was prepared by a chemical method using the synthesized FePO41.78H2O, LiOH, citric acid and PEG as raw materials. The synthesized FePO41.78H2O precursor powder was obtained by co-precipitation method. LiFePO4powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA)/differential scanning calorimetry (DSC). The results showed that the calcined LiFePO4was in a single phase when fabricated by using the synthesized FePO41.78H2O powder at pH of 3.5 in argon atmosphere.

scholarly journals Effects of pH value and Sintering Temperature on the Structural and Magnetic Properties of Barium Hexaferrites Prepared by Co-Precipitation

2021 ◽  
Vol 18 (1) ◽  
pp. 37-47
Author(s):  
Eman S. Al-Hwaitat ◽  
Mohammad K. Dmour ◽  
Ahmad S. Masadeh ◽  
Ibrahim Bsoul ◽  
Yazan Maswadeh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Permanent Magnet ◽  
Ph Value ◽  
Magnetic Measurements ◽  
Precipitation Method ◽  
Magnetic Data ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Co Precipitation

Barium hexaferrite (BaFe12O19; M-type; BaM) is an important, cost effective magnetic material for permanent magnet applications. The magnetic properties of the prepared samples, and the purity of the BaM phase depend critically on the synthesis route and experimental conditions. In this study, BaM hexaferrites were prepared by co-precipitation method using two different values of pH for the precursor solutions (11.0 and 12.5), and sintering pellets of the co-precipitates at 860, 920 and 990°C.The prepared samples were characterized using X-ray diffraction and magnetic measurements. X-ray diffraction patterns indicated that the samples prepared with pH = 12.5 consisted of a single BaM phase at all sintering temperatures. However, the patterns of the samples with pH = 11.0 did not reveal the existence of BaM at 860°C, whereasa major BaM phase (86 – 87 wt.%) was observed at 920 and 990°C with a minor α-Fe2O3 phase. The thermo magnetic curves confirmed the BaM magnetic phase in the samples. The hysteresis loops of the BaM samples showed characteristics of hard magnetic materials with relatively high saturation magnetization. Analysis of the magnetic data indicated an intrinsic coercivity Hci~ 5 kOe for all samples, and a saturation specific magnetization in the range σs = 56.0 – 66.3 emu/g, which are suitable for permanent magnet applications. The practical coercivity (HcB), residual induction (Br) and maximum energy product (BH)max of the samples with pH = 12.5 are higher than those of the samples with pH = 11.0, and the highest magnetic parameters of HcB = 1871 Oe, Br = 2384 G, and (BH)max = 8.92 kJ/m3 were observed for the sample with pH = 12.5 and sintered at 860°C.

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.

scholarly journals Crystalloquasichemical Model of Spinel CoFe2O4 Formation, Obtained by Chemical co-Precipitation Method

2015 ◽  
Vol 16 (3) ◽  
pp. 540-546 ◽  
Author(s):  
T.R. Tatarchuk ◽  
I.P. Yaremiy ◽  
N.D. Paliychuk
Keyword(s):  
Cobalt Ferrite ◽  
Phase Distribution ◽  
Surface Interactions ◽  
Precipitation Method ◽  
Boundary Phase ◽  
Surface Phenomena ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Co Precipitation

In the work the spinel cobalt ferrite synthesized by chemical co-precipitation method. The X-ray diffraction analysis and thermal analysis confirmed the crystalline structure and phase purity of the prepared ferrite. The crystalloquasichemical mechanism of formation stoichiometric cobalt ferrite through interaction by defective hydrooxide phases was described. The surface phenomena that occur on the boundary phase distribution was described. There formation of cationic and anionic vacancies, rooted cobalt atoms or oxygen atoms. Crystalloquasichemical modeling of surface interactions between Co(OH)2 and Fe(OH)3 can trace the formation of spinel structure with the participation of antistructure of matrix and reduced to the corresponding stoichiometric hydroxides species. Shows the reaction of four types of crystal impurity clusters on the surface of the hydroxide matrix and their interaction with each other to form spinel СоFe2O4.

Effect of Surfactants on Structural and Dielectric Properties of Cobalt Ferrite

2014 ◽  
Vol 938 ◽  
pp. 14-18 ◽  
Author(s):  
Hemal Khatri ◽  
G. Packiaraj ◽  
Rajshree B. Jotania
Keyword(s):  
Dielectric Properties ◽  
Cobalt Ferrite ◽  
Low Frequency ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Field ◽  
Co Precipitation ◽  
Triton X

Cobalt ferrite (Cofe2o4) particles were synthesized with and without presence of surfactants using a co-precipitation method. Three surfactants Cetyl Tri methyl Ammonium Bromide (CTAB-cationic), Sodium dodecylbenzenesulphonate (anionic), Triton X-100 (nonionic), were used and investigate their effects on the structural and dielectric properties of CoFe2O4 particles. The ferrite precursors were first pre calcined in a muffle furnace at 500°C and then calcined at 950°C. Structural, dielectric and magnetic properties of prepared particles were investigated using X-ray powder diffraction, Dielectric and Low field ac magnetic susceptibility measurement. Phase purity of prepared samples was confirmed by X-ray diffraction. The sample with surfactant Triton X-100 shows the highest values of dielectric constant at low frequency.

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

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