scholarly journals Fast Solution Synthesis of NiO-Gd0.1Ce0.9O1.95 Nanocomposite via Different Approach: Influence of Processing Parameters and Characterizations

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3437
Author(s):  
Jorge Durango-Petro ◽  
Christopher Salvo ◽  
Jonathan Usuba ◽  
Gonzalo Abarzua ◽  
Felipe Sanhueza ◽  
...  
Keyword(s):  
Ball Milling ◽  
Processing Parameters ◽  
Milling Process ◽  
Secondary Phases ◽  
Solution Synthesis ◽  
Solution Combustion ◽  
X Ray ◽  
Fast Solution ◽  
Long Time ◽  
Nanocomposite Powders

The synthesis of the nickel oxide-gadolinium doped ceria (NiO-GDC with 65:35 wt.%) nanocomposite powders with a stoichiometry of Gd0.1Ce0.9O1.95 was performed via fast solution combustion technique; using three different mixing methods: (i) CM (metal cations in an aqueous solution), (ii) HM (hand mortar), and (iii) BM (ball milling). The nanocomposite powders were calcined at 700 °C for 2 h and characterized by Transmission Electron Microscopy (TEM), X-ray fluorescence (XRF), and X-ray Diffraction XRD. The TEM and XRD analyses evidenced the well-dispersed NiO and GDC crystallites with the absence of secondary phases, respectively. Later, the calcined powders (NiO-GDC nanocomposites) were compacted and sintered at 1500 °C for 2 h. The microhardness of the sintered nanocomposites varies in accordance with the synthesis approach: a higher microhardness of 6.04 GPa was obtained for nanocomposites synthesized through CM, while 5.94 and 5.41 GPa were obtained for ball-milling and hand-mortar approach, respectively. Furthermore, it was observed that regardless of the long time-consuming ball-milling process with respect to the hand mortar, there was no significant improvement in the electrical properties.

Structural Evaluation of Ti-22.2Si-11.1B Powders Milled with PCA Addition

2008 ◽  
Vol 591-593 ◽  
pp. 147-153
Author(s):  
Gilbert Silva ◽  
Erika Coaglia Trindade Ramos ◽  
N.S. da Silva ◽  
Alfeu Saraiva Ramos
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Ball Mill ◽  
Milling Process ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Evaluation ◽  
Equilibrium Structures ◽  
Scanning Electron

A large amount of the Ti6Si2B compound can be formed by mechanical alloying and subsequent heat treatment from the elemental Ti-22.2at%Si-11.1at%B powder mixture, but the yield powder after ball milling is reduced due to an excessive agglomeration of ductile particles on the balls and vial surfaces. This work reports on the structural evaluation of Ti-22.2at%Si-11.1at%B powders milled with PCA addition, varying its amount between 1 and 2 wt-%. The milling process was carried out in a planetary ball mill under argon atmosphere, and the milled powders were then heated at 1200oC for 1h under Ar atmosphere in order to obtain equilibrium structures. Samples were characterized by X-ray diffraction, scanning electron microscopy, and thermal analysis. Results revealed that the PCA addition reduced the excessive agglomeration during the ball milling of Ti-22.2at-%Si-11.1at-%B powders. After heating at 1200oC for 1h, the Ti5Si3, Ti3O and/or Ti2C phases were preferentially formed in Ti-22.2at%Si-11.1at%B powders milled with PCA addition, and the Ti6Si2B formation was inhibited.

scholarly journals Effect of Organic Assistant on the Performance of Ceria-Based Catalysts for the Selective Catalytic Reduction of NO with Ammonia

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 357 ◽  
Author(s):  
Huang ◽  
Li ◽  
Qiu ◽  
Chen ◽  
Cheng ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Ball Milling ◽  
Catalytic Reduction ◽  
Temperature Programmed Desorption ◽  
Milling Process ◽  
X Ray ◽  
Ball Milling Process ◽  
Nh3 Scr ◽  
Temperature Programmed ◽  
Catalytic Performances

In the present study, a series of CeO2/TiO2 catalysts were fabricated by dry ball milling method in the absence and presence of organic assistants, and their catalytic performances for the selective catalytic reduction (SCR) of NO by NH3 were investigated. It was found that the addition of organic assistants in the ball milling process and the calcining ambience exerted a significant influence on the catalytic performances of CeO2/TiO2 catalysts. The nitrogen sorption isotherm measurement (BET), powder X-ray diffraction (XRD), Raman spectra, high-resolution transmission electron microscopy (HR-TEM), hydrogen temperature-programmed reduction (H2-TPR), ammonia temperature-programmed desorption (NH3-TPD), sulfur dioxide temperature-programmed desorption (SO2-TPD), thermogravimetric analysis (TG), Fourier transform infrared (FT-IR) and X-ray photoelectron spectra (XPS) characterizations showed that the introduction of citric acid in the ball milling process could significantly change the decomposition process of the precursor mixture, which can lead to improved dispersion and reducibility of cerium species, surface acidity as well as the surface microstructure, all which were responsible for the high low temperature activity of CeTi-C-N in an NH3-SCR reaction. In contrast, the addition of sucrose in the milling process showed an inhibitory effect on the catalytic performance of CeO2/TiO2 catalyst in an NH3-SCR reaction, possibly due to the decrease of the crystallinity of the TiO2 support and the carbon residue covering the active sites.

scholarly journals Characterization and x-ray absorption spectroscopy of ilmenite nanoparticles derived from natural ilmenite ore via acid-assisted mechanical ball-milling process

2017 ◽  
Vol 8 (3) ◽  
pp. 035012 ◽  
Author(s):  
Weerachon Phoohinkong ◽  
Sorapong Pavasupree ◽  
Anucha Wannagon ◽  
Samunya Sanguanpak ◽  
Kanokthip Boonyarattanakalin ◽  
...  
Keyword(s):  
Ball Milling ◽  
Absorption Spectroscopy ◽  
Milling Process ◽  
X Ray ◽  
Ball Milling Process ◽  
X Ray Absorption ◽  
Mechanical Ball Milling

Processing of Nano Hydroxyapatite from Eggshell and Seashell

2010 ◽  
Vol 659 ◽  
pp. 159-164 ◽  
Author(s):  
Gréta Gergely ◽  
Ferenc Wéber ◽  
Mihály Tóth ◽  
Attila Lajos Tóth ◽  
Zsolt E. Horváth ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Ball Milling ◽  
Milling Process ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Attrition Milling ◽  
Milling Method ◽  
Scanning Electron

Hydroxyapatite (HAp) was successfully produced from recycled eggshell, seashell and phosphoric acid by using two different type of milling method (attrition milling and ball milling). According to the analysis, the attrition milling resulted nanosize HAp even after milling, while the ball milling process provided HAp only after a 400oC, 2 h long heat treatment. The grain size in both cases were approximately preserved during the heat treatment. The effect of temperature on stoichiometry, morphology and crystallinity of HAp powders were investigated. The structures of the HAp were characterized by X-ray diffraction and Scanning Electron Microsopy.

Effect of Sintering Parameters on the Stability of Phases of the ZnFe2O4/α-Fe Nanocomposite

2012 ◽  
Vol 188 ◽  
pp. 31-36 ◽  
Author(s):  
Vasile Florin Tarța ◽  
Ionel Chicinaş ◽  
Traian Florin Marinca ◽  
Bogdan Viorel Neamţu ◽  
Florin Popa
Keyword(s):  
Milling Process ◽  
X Ray Diffraction ◽  
Chemical Homogeneity ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Stability ◽  
Nanocomposite Powders ◽  
Sintering Method ◽  
Commercial Iron

The ZnFe2O4/α-Fe nanocomposite powders were obtained by ball milling starting from ZnFe2O4 powder synthesized by classical ceramic method and commercial iron powder. Two way of milling were used for the synthesis of the ZnFe2O4/α-Fe nanocomposite. In both cases after milling process the phases are relatively uniformly distributed in material and zinc ferrite mean crystallite size decreases from micrometric range up to 11 nm for the first milling mode and up 48 nm for second milling mode. The ZnFe2O4/α-Fe nanocomposite powders were compacted by Spark Plasma Sintering method (SPS). During sintering a reaction between nanocomposite phases occurs, thus leading to the formation of ZnO and FeO. The evolution of the powders during milling and stability of the nanocomposite phases was investigated by X-ray diffraction. The powders and compacts morphology and local chemical homogeneity were investigated by scanning electron microscopy (SEM) and respectively by energy dispersive x-ray spectrometry (EDX). The influence of the sintering parameters on the stability of nanocomposites phases is studied.

Pengaruh Substitusi Ion Mn dan Ion Co Serta Ion Ti pada Pembentukan Fasa dan Sifat Magnetik Barium Hexaferrite BaFe9(MnCo)1,5Ti1,5O19 Disintesis Melalui Rute Metallurgi Serbuk

2013 ◽  
Vol 3 (01) ◽  
pp. 79
Author(s):  
Priyono P ◽  
Eddy Siradj ◽  
Azwar Manaf
Keyword(s):  
Applied Field ◽  
High Performance ◽  
Room Temperature ◽  
Barium Hexaferrite ◽  
Lattice Parameter ◽  
Partial Substitution ◽  
Powder Metallurgy Method ◽  
Secondary Phases ◽  
X Ray ◽  
Long Time

<span>Barium ferrite with hexagonal molecular BaFe<span>12<span>O<span>19 <span>is well-known for its high performance <span>permanent magnetic and good mechanical properties and attracted attention of researchers for <span>a long time. The hexaferrite powders were produced according to a conventional ceramic <span>process with powder metallurgy method. Moreover, the powders were analyzed by X-ray <span>diffraction, to detect the presence of secondary phases. The magnetic properties of the samples<br /><span>were measured at room temperature using Permeagraph with a maximum applied field of 1.5 <span>T. The calculation of the lattice parameter on conventional magnets (BaFe<span>12<span>O<span>19<span>) results a = b = <span>5,894 Å and c = 23,210 Å, while the substituted phase has a range value of a = b between <span>5,893 Å to 5,899 Å, and c lattice parameter value is in the range of 23,328 ˚A to 23,346 Å.<br /><span>With the partial substitution of Fe<span>+3 <span>ions by Mn<span>+2 <span>ions, ion Co<span>+2 <span>and Ti<span>+4 <span>ion magnetic <span>properties decrease primarily on the magnetic coercivity from 125 kA / m (conventional) to ~ 5 <span>kA /m in the substituted materials.</span></span></span></span></span></span></span></span></span></span></span><br /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

Tribochemical Effects of MoSi2 Powder in Ball Milling

2007 ◽  
Vol 336-338 ◽  
pp. 965-967
Author(s):  
Qi Zhou ◽  
Qin Ma ◽  
Shu Jun Zang ◽  
Jian Jun Liu ◽  
Cui Xia Wang
Keyword(s):  
Crystallite Size ◽  
Ball Milling ◽  
Effective Temperature ◽  
Milling Time ◽  
Early Stage ◽  
Milling Process ◽  
Temperature Factor ◽  
Milling Machine ◽  
X Ray Diffraction ◽  
X Ray

The tribochemical effects of MoSi2 powder in the ball milling process have been studied by X-ray diffraction (XRD) and QM-4H milling machine. It has been found that the intensity of diffraction peak of MoSi2 powder is continuously decreased and the width increased with the increase of milling time. Specifically, the crystallite size decreased largely in the early stage of milling. Contrary to the above, the microstrain and the effective temperature factor increased considerably. After ninety hours of milling, the crystallite size had little changes. The relations among the tribochemical effect factors are as follows: the microstrain and the effective temperature factor increase with the decrease of the crystallite size. The microstrain increases with the increase of the effective temperature factor.

scholarly journals The Activation of Mg Powder Promoted by Chloride and Activation Mechanism

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1435
Author(s):  
Xiaoxuan Wang ◽  
Xiaoyan Guo ◽  
Lixiang Zhu ◽  
Shuo Wang ◽  
Meishuai Zou ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Ball Milling ◽  
Photoelectron Spectroscopy ◽  
Hydrogen Generation ◽  
Synergistic Effects ◽  
Milling Process ◽  
Production Performance ◽  
Activation Mechanism ◽  
X Ray ◽  
Highly Active

Magnesium has bright market prospects such as generating thrust for under water engines and hydrogen production. However, the passive oxide film on the surface of magnesium powder prevents the further reaction of magnesium with water at room temperature. In this paper, highly active magnesium-based materials were prepared via ball milling pure Mg with different chlorides (NiCl2, CoCl2, CuCl2, FeCl3). The activity of the as obtained powder was analyzed through Scanning Electron Microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), synchrotron X-ray tomography, Extended X-ray Absorption Fine Structure (EXAFS), etc. Among the various compositions, the Mg-6%CoCl2 composite exhibited the best hydrogen production performance with a hydrogen generation volume of 423 mL/(0.5 g) and a conversion yield of 96.6%. The related activation mechanism was thoroughly studied, showing that the addition of chloride during ball milling can effectively break the continuity of oxide films on Mg surfaces and introduces a large number of micro defects. In addition, the EXAFS and tomography data verified that metallic cobalt was generated during the ball milling process, subsequently forming a Mg-Co micro glance cell, and the Cl− in the system accelerates the corrosion of Mg. The active mechanism can be verified as synergistic effects of micro glance cell and as-generated surface microcracks.

scholarly journals Structure and dielectric properties of (1-x)Bi 0.5 Na 0.5 TiO 3–x BaTiO 3 piezoceramics prepared using hydrothermally synthesized powders

2021 ◽  
Vol 8 (7) ◽  
pp. 202365
Author(s):  
Andrea Nesterović ◽  
Jelena Vukmirović ◽  
Ivan Stijepović ◽  
Marija Milanović ◽  
Branimir Bajac ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Pyrochlore Phase ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Low Dielectric ◽  
Long Time ◽  
Time Periods

The influence of different processing parameters and various Ba 2+ addition (up to 10 mol%) on the structure and dielectric properties of Bi 0.5 Na 0.5 TiO 3 -BaTiO 3 (BNT-BT) ceramics was investigated. The powders were hydrothermally synthesized in the alkaline environment at 180°C for different time periods. X-ray diffraction confirmed the presence of dominant rhombohedral Bi 0.5 Na 0.5 TiO 3 phase and a small amount of secondary pyrochlore Bi 2 Ti 2 O 7 phase in the pure BNT powders. In addition, one-dimensional Na 2 Ti 2 O 7 structure was also observed in the powder hydrothermally treated for a long time (i.e. 48 h). The amount of secondary pyrochlore phase in the BNT-BT powders increases with the increase of Ba 2+ content. The synthesized powders were pressed into pellets and finally sintered at various temperatures up to 1150°C. High density (more than 90%TD) was obtained in all BNT-BT sintered samples. Optimal sintering parameters were chosen in order to obtain dense ceramics with the optimal phase composition. The temperature dependence of dielectric properties for the BNT-BT ceramics was also studied. Relaxor behaviour of BNT-based ceramics and broad transition peaks are evident in all samples. Dielectric constant up to 400 as well as an acceptable low dielectric loss at temperatures lower than 200°C were obtained in BNT-BT ceramics.

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