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.

Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite

2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno
Keyword(s):  
Magnetic Properties ◽  
Gallic Acid ◽  
Precipitation Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
The Fourier Transform ◽  
The One ◽  
Co Precipitation

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.

Spinel Structured Iron Gallium Oxynitride - Fe2GaO2N2

2021 ◽  
Vol 1160 ◽  
pp. 45-50
Author(s):  
Savitha Kadencheri Unnikrishnan
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Spinel Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Novel Material ◽  
Optical And Magnetic Properties ◽  
Co Precipitation

A facile method was successfully developed to prepare Ternary oxynitride of iron and gallium. Initially mixed oxyhydroxides of Iron and gallium were prepared by co-precipitation method. Then this was nitrided using urea and agar in presence of ammonia at 900°C, which gave mixed cation oxynitride . This mixed oxynitride was characterized using XRD, XPS and SEM. The X-ray diffraction pattern of the Fex’GaxOyNz phase was refined within the cubic spinel structure (space group Fd-3m), using the fullprof program. On assuming 3+ oxidation state for half of iron and whole of gallium, the chemical composition of the oxynitride spinel determined by the X-ray analysis is Fe2GaN2O2. The refinement using these parameters resulted in a good fit to the observed diffraction data, with a crystallographic R factor of 5.92. This ternary oxynitride of iron and gallium is a novel material which can give unique optical and magnetic properties.

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.

scholarly journals Influence of the Local Structure on the Photocatalytic Properties of Zinc Spinel Ferrite Nanoparticles

2021 ◽  
Author(s):  
Luciana Biazati ◽  
Lucas Lorenzini ◽  
Sandra Ferreira ◽  
Arilza Porto ◽  
Eustáquio de Castro ◽  
...  
Keyword(s):  
Uv Light ◽  
Spinel Ferrite ◽  
Indigo Carmine ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Tetrahedral Sites ◽  
Co Precipitation ◽  
X Ray Absorption

The correlation between iron distribution in octahedral or tetrahedral sites in synthetic magnetite and zinc spinel ferrites and their catalytic properties were investigated in this work. The zinc‑doped nanomagnetites were prepared by co-precipitation method and annealed at 420 °C. X-ray diffraction, UV-Vis, X-ray absorption and 57Fe Mössbauer spectroscopies were used to identify iron sites. The obtained results showed that ZnII replaces the relatively smaller FeIII cation in the tetrahedral sites, increasing the cubic lattice dimension, and this replacement remarkably enhances the catalytic effectiveness of the Zn-spinel ferrite towards the indigo carmine degradation compared to undoped magnetite. The indigo carmine degradation experiments were carried out using photo-Fenton method in which 50 mL of indigo carmine dye aqueous solutions (20 mg L−1, pH 3.0), 20 mg ZnxFe(3-x)O4, and 2.0 mL H2O2 (aqueous solution at 0.028 mol L−1) were placed under UV light at 25 °C. Under these experimental conditions the degradation rate of indigo carmine was superior to 98%.

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 Lanthanum-Strontium Manganites by a Hydroxide-Precursor Co-Precipitation Method in Solution and in Reverse Micellar Microemulsion

2005 ◽  
Vol 494 ◽  
pp. 155-160 ◽  
Author(s):  
V. Uskoković ◽  
Darko Makovec ◽  
Miha Drofenik
Keyword(s):  
Reverse Micelles ◽  
Magnetic Measurements ◽  
Precipitation Method ◽  
Bulk Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Conditions ◽  
Lanthanum Strontium ◽  
Transmission Electron ◽  
Co Precipitation

Nanostructured lanthanum-strontium manganites have been synthesized using two different co-precipitation approaches, one in bulk solution, and the other in reverse micelles of CTAB/1-hexanol/1-butanol/water microemulsion. In both cases, precursor cations were precipitated by alkali precipitating agents. The properties of the material synthesized by using these two methods were compared in order to reveal potential advantages of microemulsion-assisted approach. The influence of the annealing conditions on the properties of synthesized manganites was investigated by using X-ray diffraction, transmission electron microscopy, differential thermal analysis, thermogravimetric analysis and magnetic measurements.

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 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.

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

Sign in / Sign up

Export Citation Format

Share Document