Papers by Abolghasem Ataie
Strontium carbonate (SrCO3) is one of the most important strontium compounds that have been used ... more Strontium carbonate (SrCO3) is one of the most important strontium compounds that have been used in a variety of technological and industrial applications. In the present investigation, nano-structured strontium carbonate was synthesized by mechano-chemical reaction of celestite ore (SrSO4) collected from Dasht-e kavir, Iran and sodium carbonate during high energy mechanical milling.The milling were performed for different durations of time up to 16 hours in a high-energy planetary ball mill with the rotational speed and ball to powder weight ratio of 300 rpm and 30, respectively. X-Ray diffraction (XRD), X-ray fluorescence spectrometer (XRF) and scanning electron microscope (SEM) were used to characterize the obtained samples. XRD results showed that at a Na2CO3:SrSO4 molar ratio of 1.05:1, mechano-chemical reaction started after 1 hour of milling. Although the longer milling times gives a more conversion of SrSO4 to SrCO3 but it has not been completed even after 16 hours of millin...
Silicon nanoparticles are the focus of attention thanks to their potentialities in advanced appli... more Silicon nanoparticles are the focus of attention thanks to their potentialities in advanced applications such as new batteries, photovoltaic cells and so on. The need to porous silicon is thus rising and will follow the same trend. In this work, highly porous nanostructured silicon is synthesized via Self-propagating high-temperature synthesis (SHS) route. Microstructural and phase analyses show that the employed technique is capable of producing a three-dimensional porous silicon which can act as a skeleton for embedding lithium ions and therefore, resisting large volume expansions arising during lithiation phase. Considering the fact that the wave front experiences high temperatures (above 1900°C) which can result in nanoparticles’ sintering, and in order to improve the porosity level, ammonium nitrate is used as a neutral additive at Mg/SiO2/NH4NO3 (2.4:1:0.1) molar ratio. The influence of nitrate addition on the final microstructure is studied through comparing salt-added sample...
Although Cu and Fe are immiscible under equilibrium conditions, they can form supersaturated soli... more Although Cu and Fe are immiscible under equilibrium conditions, they can form supersaturated solid solutions by mechanical alloying. In this paper, nano-structured of the metastable Cu-Fe phase containing 10, 15, 20 and 25% wt Fe were synthesized by intensive ball milling for 15h, in order to achieve a solid solution of Fe in Cu. The phase composition, dissolution of the Fe atoms into the Cu matrix, and the morphology of the milling products were studied by X-ray Diffraction (XRD), Energy Dispersive Spectrometer (EDS), and Field Emission Scanning Electron Microscope (FESEM) techniques, respectively. The mean crystallite size of the milled samples was determined by XRD peak broadening using the Williamson-Hall approximation. The XRD analysis results showed that the solid solubility of the Fe in the Cu was extended to 20%wt after milling for 15 h, and a homogeneous solid solution of Cu80Fe20 with a mean crystallite size of 19nm was obtained. The mean crystallite size decreased with in...
Advanced Powder Technology, 2020
The crystallization behaviors of mechanically alloyed amorphous Fe-Ti alloys were studied. The a-... more The crystallization behaviors of mechanically alloyed amorphous Fe-Ti alloys were studied. The a-Fe phase formed during annealing as a result of the devitrification of the amorphous phase. According to the Kissinger plot, the crystallization activation energy (E) was obtained as 171 kJ/mol, which is close to the activation energy for the diffusion of Fe in a-Ti. According to the non-isothermal Johnson-Meh l-Avrami (JMA) analysis and obtaining the volume fraction of the crystalline phase from the differential scanning calorimetry (DSC) plots, the average Avrami exponent (n) was determined as 1.61 and 5.67 for low and high heating rates, respectively. Moreover, a method for obtaining the value of E based on the non-isothermal JMA analysis was proposed. The value of E was determined as~185 and 191 kJ/mol respectively for low and high heating rates, which are consistent with the value determined from the Kissinger plot for all heating rates.
Solid State Ionics, 2020
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Materials Chemistry and Physics, 2018
doped LaFe(Co)O perovskite; synthesis, 3 characterization and catalytic behavior, (2017), doi: 10... more doped LaFe(Co)O perovskite; synthesis, 3 characterization and catalytic behavior, (2017), doi: 10.1016/j. Materials Chemistry and Physics matchemphys.2017.11.030 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Materials Today Communications, 2018
Transactions of Nonferrous Metals Society of China, 2016
Abstract Production of Cu–Cr/carbon nanotube (CNT) hybrid nano-composite by wet and dry milling p... more Abstract Production of Cu–Cr/carbon nanotube (CNT) hybrid nano-composite by wet and dry milling processes at three different levels of milling energy was investigated in order to study the effect of milling energy in two different media on dispersion of CNTs, and preparation of the nano-composite. The structural evolution and solid solution formation were evaluated by X-ray diffraction technique. The microstructure was characterized by scanning electron microscopy and transmission electron microscopy. Also, the mechanical properties were measured by microhardness test. The mean crystallite size was in the range of 20–63 nm depending on milling medium and energy. CNTs dispersion is a function of milling energy. According to FESEM images and microhardness results, it can be concluded that wet milling is more applicable in dispersing CNTs homogeneously in comparison to dry milling. It was also found that wet milling at higher milling energies can be a beneficial method of producing the homogeneous hybrid nano-composite with the least damages introducing on CNTs because of the higher microhardness which can be attributed to better dispersion of less damaged CNTs. Compared with crystallite size changes, CNTs dispersion and damages were considerably more effective on hardness.
Journal of Porous Materials, 2015
Cobalt ferrite nanopowders with an average particle size of 50 nm were synthesized by a modified ... more Cobalt ferrite nanopowders with an average particle size of 50 nm were synthesized by a modified Pechini type sol–gel method. Obtained powder was subjected for fabrication of magnetic foams by using microwave and conventional sintering approaches coupled by space holder method. Carbamide was used as space holder material. Samples were characterized by X-ray diffraction, stereomicroscope, scanning and transmission electron microscope, nitrogen gas adsorption–desorption, and vibration sample magnetometer analyses. The results revealed that microwave sintering offered magnetic foams with surface area of 5.21 m2/g which is four times greater than the samples obtained by conventional sintering. Such a mesoporous nanostructure was achieved only after 5 min of microwave sintering which yielded monolith foams with sufficient strength and grain growth suppression of nanostructure. Moreover, magnetic studies indicated that magnetic parameter of squareness ratio for microwave sintered foams is twice greater than that of conventionally sintered foams.
Nanostructured Cu-20Fe alloy was synthesized by mechanical alloying process and the effects of pr... more Nanostructured Cu-20Fe alloy was synthesized by mechanical alloying process and the effects of process control agents (PCA) on the phase formation, crystallite refinement and morphology of powder particles were studied. The dissolution of Fe into Cu matrix and the morphology of powder particles were analyzed by X-ray diffraction (XRD) technique and scanning electron microscopy (SEM), respectively. The mean crystallite size was approximated by the method developed by Williamson and Hall. It was found that in the absence of PCA (Toluene in the present work), the iron peaks vanish after 5 h of mechanical alloying process and the mean crystallite size of the matrix decreases to 35 nm and large agglomerated particles are formed during milling. In this regard, it was found that the addition of PCA decreases the rate of crystallite refinement and formation of solid solution but does not affect the final mean crystallite size. It was also found that the addition of PCA during milling decrea...
International Journal of Minerals, Metallurgy, and Materials, 2016
In this paper, the Taguchi method with an L 9 (3 4) orthogonal array was used as experimental des... more In this paper, the Taguchi method with an L 9 (3 4) orthogonal array was used as experimental design to determine the optimum conditions for preparing ZnO nanoparticles via a mechanothermal route. ZnSO 4 •H 2 O and Na 2 CO 3 were used as starting materials. The effects of milling time, Na 2 CO 3 /ZnSO 4 •H 2 O molar ratio, and ball-to-powder mass ratio (BPR) on the bandgap (E g) of ZnO nanoparticles were investigated. The ranges of the investigated experimental conditions were 5-15 h for the milling time (t), 1.0-1.2 for the Na 2 CO 3 /ZnSO 4 •H 2 O molar ratio (M), and 10-30 for BPR. The milling time and BPR exhibited significant effects; an increase in milling time reduced the bandgap. The optimum conditions from this study were t 3 = 15 h, M 1 = 1, and BPR 2 = 20. Only two significant factors (t 3 , 15 h; BPR 2 , 20) were used to estimate the performance at the optimum conditions. The calculated bandgap was 3.12 eV, in reasonable agreement with the experimental results obtained under the optimized conditions.
Journal of Materials Science, 1993
Si 3 N 4-MoSi 2 in situ composite has been synthesized by reacting powders of molybdenum (Mo) and... more Si 3 N 4-MoSi 2 in situ composite has been synthesized by reacting powders of molybdenum (Mo) and silicon nitride (Si 3 N 4). Mo and Si 3 N 4 powders mixture in a molar ratio of 1:3 were ball milled for 0-100 h. The milled and unmilled powder mixtures were reacted at different temperatures between 1000 and 1600 • C in an argon atmosphere. The effect of mechanical activation (MA) induced by milling has been studied through X-ray diffraction (XRD), differential thermal analysis (DTA), and thermo-gravimetric analysis (TGA). No peaks of Mo in the XRD pattern have been observed after 70 h of milling. The crystallite size of the Mo has been found to be the lowest (41 nm) after milling for 30 h. Similarly, a 100 nm lowest size of crystallite of Si 3 N 4 was observed after milling for 50 h. DTA and TGA results show that the reaction between Mo and Si 3 N 4 enhances with increase in milling time. Milling for 10 h lowers the pyrolysis temperature by 150 • C. Additional milling upto 100 h does not lead to further reduction in the pyrolysis temperature. The intensities of peaks of MoSi 2 in the pyrolysed samples increased with increase in milling time. MoSi 2 particles of size less than 1 m were observed to be uniformly distributed through out the Si 3 N 4 matrix.
Materialwissenschaft und Werkstofftechnik, 2020
Mechanical alloying, cold pressing, and sintering were used for synthesizing bulk copper, copper-... more Mechanical alloying, cold pressing, and sintering were used for synthesizing bulk copper, copper-iron, and copper-iron-silicon carbide nanomaterials. The precipitation of iron during sintering of the supersaturated mechanically alloyed powder significantly enhanced the thermal stability of the nanocomposite against grain growth. Moreover, the hardness of sintered composites was found to increase with increasing milling time, which was attributed to the work-hardening, crystallite refinement, and increasing the relative density (decrease in porosity). Although the addition of silicon carbide did not affect the mean crystallite size of the bulk samples, it effectively increased the hardness of the nanocomposite based on its composite strengthening effect.
Materials Research Bulletin, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Titanium diboride (TiB 2) is a refractory ceramic which has excellent properties such as high mel... more Titanium diboride (TiB 2) is a refractory ceramic which has excellent properties such as high melting point, high hardness, good thermal and electrical conductivity, high wear resistance and considerable chemical stability[1, 2]. A mixture of TiO 2 , H 3 BO 3 and Mg with a stoichiometric ratio has been mechanically activated in a planetary high energy ball mill for 5, 10, 15 and 20 h and then compacted. Nano-size particles of TiB 2 were synthesized by self propagating high temperature synthesis route through putting a hot filament on top of the compact mixture. Effects of the milling time and addition of NaCl as process diluents on the phase composition and morphology of the products were investigated. The X-ray diffraction patterns indicated the formation of TiB 2 together with MgO and some minor intermediate phases like Mg 3 B 2 O 6 and Mg 2 TiO 4 in the un-milled sample. Nano-crystalline TiB 2 with mean crystallite size of 36 nm became the major phase in the leached sample by HCl...
Silica exists in Rice husk, an agriculture waste, as a naturally occurring phase. In first step, ... more Silica exists in Rice husk, an agriculture waste, as a naturally occurring phase. In first step, acidic pre-treatment and calcination of the rice husk were performed to obtain nano-silica, in which various sizes of the nano-silica, totally with sizes under 80 nm, were achieved. Second, to reduce nano-silica to elemental Si and subsequently formation of the composite, Mg used as the reducing agent. In this work, the as-obtained composite mainly is the product of magnesiothermic reduction reaction of the nano-silica, which finally resulted in formation of elemental Si (silicon), MgO (magnesia) and Mg2SiO4 (magnesium silicate). The as-synthesized composite can be used as anode in lithium ion batteries. The products in each step were characterized using X-ray powder diffraction (XRD) and scanning electron microscopy (FESEM and HRSEM) techniques. X-ray powder diffraction patterns confirmed the formation of almost amorphous silica while the FE-SEM images were representing the spherical si...
Ceramics International, 2020
Nanostructured Sr 2 FeMoO 6 double perovskite was synthesized by the sol-gel combustion method. X... more Nanostructured Sr 2 FeMoO 6 double perovskite was synthesized by the sol-gel combustion method. X-ray diffraction results showed that SrMoO 4 starts to form at 450°C, and the formation of single-phase double perovskite with a tetragonal I4/m space group occurs at a relatively low temperature of 750°C. Rietveld refinement by FullProf software showed the mean crystallite size of 49 nm, and unit cell parameters of a = b = 5.577 Å and c = 7.918 Å for the synthesized Sr 2 FeMoO 6. Analysis of the FTIR spectra revealed that with mechanical activation process, the peak corresponding to the CO band at 2341 cm −1 vanishes and intensity of carboxyl group (1445 cm −1) and nitrate ions band (1396 cm −1) are affected. The presence of the peaks related to the vibration of metal ions bands at octahedral sites at 644 and 831 cm −1 confirms the evolution of Sr 2 FeMoO 6 double perovskite structure. Scanning electron microscope images showed that the Sr 2 FeMoO 6 powder processed at 750°C in 5%H 2 /N 2 atmosphere has a mean particle size of about 250 nm. It was observed that the saturation magnetization increases to the high value of 18 emu.g −1 in the ordered structure at 800°C. High Curie temperature of 423 K in the prepared sample makes it a promising candidate for the magnetocaloric applications.
In this research, the effect of different biopolymers such as polyethylene glycol (PEG) and polyv... more In this research, the effect of different biopolymers such as polyethylene glycol (PEG) and polyvinylalcohol (PVA) on synthesis and characterization of polymer/cobalt ferrite (CF) nano-composites bymechanical alloying method has been systematically investigated. The structural, morphological andmagnetic properties changes during mechanical milling were investigated by X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), fieldemission scanning electron microscopy (FESEM), and vibrating sample magnetometer techniques(VSM), respectively. The polymeric cobalt ferrite nano-composites were obtained by employing atwo-step procedure: the cobalt ferrite of 20 nm mean particle size was first synthesized by mechanicalalloying route and then was embedded in PEG or PVA biopolymer matrix by milling process. Theresults revealed that PEG melted due to the local temperature raise during milling. Despite thisphenomenon, cobalt ferrite nano-pa...
In this study the characteristics of two different kinds of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) powders... more In this study the characteristics of two different kinds of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) powders, one in-house synthesized powder by a co-precipitation method and another one purchased from Fuel Cell Materials Co. (FCM Co., USA), were compared. The co-precipitated powder was prepared by using ammonium carbonate as precipitant with a NH4+/NO3- molar ratio of 2 and calcination at 1000C for 1 h. Phase composition, morphology and particle size distribution of powders were systematically studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and laser particle size analysis (LPSA), respectively. The synthesized and commercial LSCF powders were overlaid on Yttria-stabilized zirconia (YSZ) electrolyte having a gadolinium-doped ceria (GDC) interlayer. Electrochemical Impedance Spectroscopy (EIS) measurement was carried out at various operating temperatures in the range of 600-850C. XRD and FESEM analysis revealed that single phase nano-crystalline LSCF...
Nano-structured lanthanum strontium cobalt ferrite, La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), was successful... more Nano-structured lanthanum strontium cobalt ferrite, La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), was successfully synthesized via co-precipitation method using metal nitrates as starting materials. Effects of precipitating agent and calcination temperature on the phase composition and morphology of synthesized powders were systematically studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. XRD analysis revealed that a single phase La0.6Sr0.4Co0.2Fe0.8O3 perovskite was obtained in the processed sample using ammonium carbonate as precipitating agent with a NH4+/NO3-molar ratio of 2 after calcination at 1000C for 1 h. The phase composition of products was also affected by changing pH values. Moreover, using sodium hydroxide as a precipitant resulted in a mixture of La0.6Sr0.4Co0.2Fe0.8O3 and cobalt ferrite (CoFe2O4) phases. Careless washing of the precursors can also led to the formation of mixed phase after calcination of final powders. Mean ...
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Papers by Abolghasem Ataie
activation of Bi2O3 and Fe2O3 with the molar ratio of 1:1, using a planetary high energy ball mill
and subsequent heat treatment. All samples were milled for 20 h and heat treated at various
temperatures. XRD, FESEM, LPSA, and VSM techniques were used to evaluate the powder
particle characteristics. FESEM images of 20 h milled sample indicated plate-like particles with a
mean thickness of 45 nm and its LPSA results showed the mean agglomerate size of about 2.0 μm.
XRD results of calcined samples showed that the BFO phase began to form at 650 °C and fully
formed at 750 °C. In comparison to the conventionally processed samples, BFO phase formation
temperature decreases by ∼100 °C in the samples produced by mechanical activation assisted
process. VSM measurements of the sample heat treated at 750 °C revealed a saturation
magnetization (Ms) of 0.054 emu/g and coercivity (Hc) of 412 Oe.