scholarly journals Formation of anorthite containing cordierite materials through reaction sintering kaolin, MgO and CaO precursors

2020 ◽  
Vol 52 (2) ◽  
pp. 135-147
Author(s):  
Smail Lamara ◽  
Djaida Redaoui ◽  
Foudil Sahnoune ◽  
Menad Heraiz ◽  
Nouari Saheb
Keyword(s):  
Room Temperature ◽  
Diffraction Method ◽  
Nucleation And Growth ◽  
The Other ◽  
Formation Temperature ◽  
Reaction Sintering ◽  
Heating Rates ◽  
Powder Mixtures ◽  
X Ray ◽  
Two Samples

The effect of CaO on cordierite formation from kaolin-MgO-CaO powder mixtures, milled for 5 h and reaction sintered for 2 h in the temperature range 900-1400?C, was investigated. Phases formed in the developed materials were characterized by x-ray powder diffraction method (XRD) and Raman spectroscopy. Non-isothermal differential thermal analysis (DTA) and thermogravimetric (TG) experiments were performed from room temperature to 1400?C, at heating rates from 20 to 40?C/min. Activation energies were determined using Kissinger method. It was found that sintering the stoichiometric kaolin-magnesia mixture led to the nucleation and growth of monolithic cordierite; while cordierite along with anorthite were present in the other two samples where 4 or 8 wt% of CaO was added. The increase in CaO decreased cordierite formation temperature and increased the activation energy, which ranged from 445 to 619 kJ/mol for ?-cordierite and from 604 to 1335 kJ/mol for ?-cordierite.

Structural Properties of 300 Å of Iron Films Grown on Polycrystalline Substrate

2019 ◽  
Vol 397 ◽  
pp. 69-75
Author(s):  
Radhia Boukhalfa ◽  
Hichem Farh
Keyword(s):  
Structural Properties ◽  
Room Temperature ◽  
Molecular Beam ◽  
Structural Characteristics ◽  
Diffraction Method ◽  
The Other ◽  
X Ray Diffraction ◽  
Iron Films ◽  
X Ray ◽  
Polycrystalline Substrate

In this manuscript, the structural properties such as the distance inter-reticular of samples is studied, In the fact, four samples were used symbolized as follows: E tAg(Å), the only difference is the thickness of the Silver buffer layer (tAg= 0, 50, 100 and 150 Å) to find out how the thickness of this layer depends on the structural characteristics of the Iron thin layer, all samples are deposited using molecular beam epitaxy (MBE) at room temperature onto Si (100) substrate. The structural properties of all samples examined using X-ray diffraction method at small and high angles. The small angles X-Ray diffraction curves confirmed to us that there is a clear difference between the surface structure of the samples by varying the number of Kiessig Fringes, Also high angles X-Ray diffraction curves assured us this difference through the clear variation in the angular positions of the peaks of Bragg and the distances inter-reticular values from a sample to the other.

The Influence of Tribophysical Activation on Non-Isothermal Sintering of BaTiO3 Ceramics

2006 ◽  
Vol 514-516 ◽  
pp. 1566-1570 ◽  
Author(s):  
Vera P. Pavlović ◽  
Maria V. Nikolić ◽  
V. Spasojević ◽  
Jovan Blanuša ◽  
Ljiljana Živković ◽  
...  
Keyword(s):  
Barium Titanate ◽  
Powder Diffraction ◽  
Ball Mill ◽  
Room Temperature ◽  
Diffraction Method ◽  
Heating Rates ◽  
Technological Parameters ◽  
Dilatometric Analysis ◽  
X Ray ◽  
Scanning Electron

In this paper the influence of tribophysical activation on non-isothermal sintering of barium titanate has been investigated. BaTiO3 powders were tribophysically activated in a planetary ball mill for 0, 60 and 120 min., pressed and non-isothermally sintered up to 1380oC. Dilatometric analysis was performed in air in the temperature range from room temperature to 1380oC with heating rates of 10, 20 and 30oC/min. The samples were analyzed by the X-ray powder diffraction method. Investigation of the morphology of microstructure constituents was performed using the scanning electron microsocopy method. With the purpose of optimizing technological parameters the results obtained by microstructure analysis were correlated with the results of quantitative dilatometric analysis.

Mechanically Driven Dissolution of Sn in Near-Equiatomic Bcc FeCo

2012 ◽  
Vol 194 ◽  
pp. 187-193 ◽  
Author(s):  
J.M. Loureiro ◽  
Benilde F.O. Costa ◽  
Gerard Le Caër ◽  
Bernard Malaman
Keyword(s):  
Magnetic Field ◽  
Solid Solutions ◽  
Room Temperature ◽  
Hyperfine Magnetic Field ◽  
Ternary Alloys ◽  
119Sn Mössbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray

Ternary alloys, (Fe50−x/2Co50−x/2)Snx(x ≤ 33 at.%), are prepared by mechanical alloying from powder mixtures of the three elements. As-milled alloys are studied by X-ray diffraction and 57Fe and 119Sn Mössbauer spectroscopy. The solubility of Sn in near-equiatomic bcc FeCo is increased from ~0.5 at. % at equilibrium to ~20 at.% in the used milling conditions. The average 119Sn hyperfine magnetic field at room temperature is larger, for any x, than the corresponding fields in mechanically alloyed Fe-Sn solid solutions.

Study on Schottky Diode Characteristics Improving by X-Ray Irradiation

2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  
Keyword(s):  
Leakage Current ◽  
Schottky Diode ◽  
Room Temperature ◽  
The Other ◽  
Low Power Consumption ◽  
Initial Value ◽  
X Ray ◽  
Forward Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.

ROOM TEMPERATURE MAGNETIC ANOMALIES IN BENZENE TREATED Bi–Pb–Sr–Ca–Cu–O POWDER

1991 ◽  
Vol 05 (21) ◽  
pp. 1447-1456 ◽  
Author(s):  
A. R. HARUTUNYAN ◽  
L. S. GRIGORYAN ◽  
A. S. KUZANYAN ◽  
A. A. KUZNETSOV ◽  
A. A. TERENTIEV ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chemical Composition ◽  
Room Temperature ◽  
Microprobe Analysis ◽  
Magnetic Anomalies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Samples ◽  
Field Dependent ◽  
History Of

Two samples of benzene-treated Bi–Pb–Sr–Ca–Cu–O powder exhibited at 300 K magnetic field dependent diamagnetism and magnetization irreversibility. The treatment with benzene resulted also in the appearance of microwave absorption at low magnetic fields, while is sensitive to magnetic history of the sample. From X-ray diffraction data one can see that upon benzene treatment the reflections of 85 K and 110 K phases do not change practically, but a series of new reflections appeared, indicating a lattice modulation with 4.9 nm periodicity. A microprobe analysis revealed substantial inhomogeneity of chemical composition across the samples. The room temperature anomalies were weakened in one sample and vanished in the second upon thermal cycling.

Fabrication of Bi6Fe2Ti3O18 Ceramics by Mixed Oxide Method

2012 ◽  
Vol 730-732 ◽  
pp. 100-104
Author(s):  
Agata Lisińska-Czekaj
Keyword(s):  
Room Temperature ◽  
Ceramic Powder ◽  
Diffraction Method ◽  
Elementary Cell ◽  
X Ray Diffraction ◽  
Stoichiometric Mixture ◽  
Pressing Method ◽  
X Ray ◽  
Cell Parameters ◽  
Ceramic Samples

In the present study Bi6Fe2Ti3O18 (BFTO) ceramics has been fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, TiO2 and Fe2O3. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements have shown conservation of the chemical composition of the ceramic powder after calcination. Hot-pressing method was used for final densification of ceramic samples. The crystalline structure of the sintered samples was examined by X-ray diffraction method at room temperature. It was found that BFTO ceramics sintered at T=980 °C adopted the orthorhombic structure of Aba2 (41) space group with the following elementary cell parameters: a=5.4567(2)Å, b=49.418(2) and c=5.4826(2). Details concerning the atom’s positions are presented.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. VII Acid Salts of the 4-Nitrophenoxides of Group 2

1998 ◽  
Vol 51 (8) ◽  
pp. 785 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Calcium Salt ◽  
Three Dimensional ◽  
Closed Shell ◽  
The Other ◽  
X Ray ◽  
C 23 ◽  
Structure Determinations ◽  
Group 2 ◽  
Acid Salts

Room-temperature single-crystal X-ray structure determinations are recorded for a number of Group 2 4-nitrophenoxide acid salts, variously hydrated M(4-np)2.x(4-npH).yH2O. Ca(4-np)2.2(4-npH).8H2O is monoclinic, P 21/n, a 30·52(1), b 10·027(1), c 23·65(2) Å, β 116·3(5)°, Z = 8, conventional R on |F| being 0·058 for No 5092 independent ‘observed’ (I > 3s(I)) reflections. Sr(4-np)2.2(4-npH).8H2O, based on a subcell of the former, is monoclinic, P 21/c, a 15·576(5), b10·081(6), c 24·20(2) Å, β 117·99(5)° , Z = 4, R 0·054 for No 2908. Ba(4-np)2.2(4-npH).4H2O is orthorhombic, Fdd2, a 28·01(1), b 19·90(1), c 10·692(7)Å, Z = 8, R 0·028 for No 1967. The strontium array (and that of the calcium salt developed from it) may be represented as [(H2O)6Sr(4-npH.4-np)] (4-npH.4-np), a neutral ligand being unsymmetrically chelated to the strontium through the nitro group, with a quasi-parallel counter ion hydrogen-bonded to it by phenoxide confrontation. The other two 4-np residues make up a similar phenoxide-confronting pair (4-npH.4-np), the hydrogen being more intimately associated with one moiety. The barium salt is also an interesting array: the 10-coordinate barium lies on a crystallographic 2 axis, in an environment of two pairs of symmetry-related nitro-chelating ligand anions, and a pair of nitro-O coordinating neutral 4-npH ligands; the whole [(H2O)4Ba(4-np)2(4-npH)2] array may be envisaged as a single neutral (super)molecule. Hydrogen bonds between confronting phenoxides of the neutral 4-npH components of the parent and the 4-np- components of neighbouring molecules link the whole into a three-dimensional array.

Synthesis and Structure of the Binuclear 1 : 1 Silver(I) 2-Hydroxy-3,5-dinitrobenzoate/Triphenylphosphine Complex

2003 ◽  
Vol 56 (7) ◽  
pp. 718
Author(s):  
A. Hamid bin Othman ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Structure Determination ◽  
Room Temperature ◽  
The Other ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Phenolic Oxygen ◽  
Triphenylphosphine Complex ◽  
Silver Atoms

A room-temperature single-crystal X-ray structure determination of the 1 : 1 adduct of silver(I) 2-hydroxy-3,5-dinitrobenzoate/triphenyl-phosphine (AgL/PPh3) was recorded, showing it to be a binuclear centrosymmetric system with the silver atoms bridged by one of the carboxy oxygen atoms of each ligand, [(PPh3)Ag(μ-O)2Ag(PPh3)] as in the parent acetate; the phenolic oxygen, retaining its protonation, is hydrogen bonded within the ligand to the other feebly chelating carboxylate oxygen.

The Influence of Emulsifiers on the Crystal Properties of Tristearin and Trilaurin

1988 ◽  
Vol 3 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J. Schlichter ◽  
I. Mayer ◽  
S. Sarig ◽  
N. Garti
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Diffraction Method ◽  
The Other ◽  
Sorbitan Monostearate ◽  
X Ray Diffraction ◽  
Sorbitan Monolaurate ◽  
X Ray ◽  
Crystal Properties ◽  
Long Chain

AbstractThe effect of solid emulsifiers, added at the level of 10%, on the lattice parameters of tristearin and trilaurin, has been studied by powder X-ray diffraction method. The presence of sorbitan monostearate and glycerol-l-stearate affects slightly the lattice constant a in tristearin; on the other hand, although sorbitan monostearate causes an increase in a of trilaurin, glycerol-l-stearate does not. The presence of sorbitan monolaurate and glycerol-l-laurate affect a of trilaurin similarly to the long chain emulsifiers.A correlation between the effect on a and the increase in melting point has been found.The presence of the emulsifier does not alter drastically the lattice dimensions of the fat. The slight dissimilarity in crystal structure between tristearin and trilaurin is confirmed by the diverse effects of the emulsifiers on the internal structure of the fat.

Effect of Nd on Microstructures and Properties of AZ31 Wrought Mg Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 301-304
Author(s):  
Wei Qiu ◽  
En Hou Han ◽  
Lu Liu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Mg Alloys ◽  
The Other ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructures And Mechanical Properties ◽  
Re Elements

Addition of RE elements to Al-containing Mg alloys can improve properties of Mg alloys at elevated temperatures. In the present investigation, hot-extruded AZ31+x%Nd. (x=0.1,0.3,0.6and1.0 wt%) wrought Mg alloy were prepared .The effects of Nd on microstructures and mechanical properties at room temperature of new alloy were investigated. The investigation found that Nd can bring about two kind of precipitation phases . One is AlNd phase, the other is AlNdMn phase, which were identified as Al11Nd3 and Al8NdMn4 by X-ray diffraction and TEM.

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