A Micro-Raman Study of Niobium Titanium Oxide Powders Obtained by Laser-Induced Synthesis

1996 ◽  
Vol 454 ◽  
Author(s):  
L. E. Depero ◽  
L. Sangaletti ◽  
E. Bontempi ◽  
R. Salari ◽  
C. Casale ◽  
...  
Keyword(s):  
Rutile Phase ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Particle Size Distributions ◽  
X Ray ◽  
Oxide Powders ◽  
Nb Content ◽  
Different Temperatures ◽  
Raman Study ◽  
Diffraction Patterns

ABSTRACTMicroraman and scanning electron microscopy studies have been performed on pure TiO2 and Nb-Ti-O nanopowders obtained by laser induced synthesis. The effect of Nb content on the temperature of the anatase to rutile phase transformation, induced by annealing in air at different temperatures, has been evidenced and related to the changes in the particle size distributions obtained from a Fourier analysis of the X-ray diffraction patterns.

Phase and Particle Size Analysis of SnO2 Nanomaterials

2015 ◽  
Vol 1109 ◽  
pp. 314-318
Author(s):  
Nor Diyana Abdul Aziz ◽  
Kelimah Elong ◽  
Norlida Kamarulzaman
Keyword(s):  
Particle Size ◽  
Particle Size Analysis ◽  
Annealed Sample ◽  
Degree Of Crystallinity ◽  
Size Analysis ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Particle Size Distributions ◽  
X Ray ◽  
Particle Sizer

Tin Oxide (SnO2) is a metal oxide which has many applications in industry. In this study, SnO2 powders were synthesized by a self-propagating combustion (SPC) method. The product was annealed at 800 °C for 12 and 24 h before characterizing with X-Ray Diffraction (XRD) for phase studies. X-Ray Diffraction results showed that both samples are pure of tetragonal structure with space group P42/mnm. The sample annealed at a longer period, that is, 24 h, shows a higher degree of crystallinity compared to the 12 h annealed sample. It also shows a smaller full width at half maximum (FWHM), indicating larger crystallite size for the 24 h annealed sample. The particle size analysis reveals that there are two groups of particle size distributions for both samples. SEM results give values that are different from the particle sizer results due to the different nature of the measurement methods.

X-Ray Diffraction Analysis of the Calcium Carbonate Polymorphs

1970 ◽  
Vol 14 ◽  
pp. 29-37 ◽  
Author(s):  
S. T. Silk ◽  
S. Z. Lewin
Keyword(s):  
Calcium Carbonate ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Particle Size Distributions ◽  
Ray Method ◽  
X Ray ◽  
Packing Efficiency ◽  
Integrated Intensities ◽  
Packing Effect ◽  
Calcium Carbonate Polymorphs

AbstractIt is shown that the integrated intensities of diffraction lines from calcite and aragonite powders prepared by precipitation vary markedly, due to variations in sample packing efficiency arising from different degrees of polydispersity in the particle size distributions. Since prolonged grinding to equalize initially divergent distributions changes the polymorph composition, the packing effect imposes the principal limitation on the precision of the x-ray method for certain types of calcium carbonate preparations.

X-ray diffraction Warren–Averbach mullite analysis in whiteware porcelains: influence of kaolin raw material

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 471-485 ◽  
Author(s):  
Angel Sanz ◽  
Joaquín Bastida ◽  
Angel Caballero ◽  
Marek Kojdecki
Keyword(s):  
Crystallite Size ◽  
Firing Temperature ◽  
Microstructural Analysis ◽  
Stoichiometric Composition ◽  
Raw Material ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes

ABSTRACTCompositional and microstructural analysis of mullites in porcelain whitewares obtained by the firing of two blends of identical triaxial composition using a kaolin B consisting of ‘higher-crystallinity’ kaolinite or a finer halloysitic kaolin M of lower crystal order was performed. No significant changes in the average Al2O3 contents (near the stoichiometric composition 3:2) of the mullites were observed. Fast and slow firing at the same temperature using B or M kaolin yielded different mullite contents. The Warren–Averbach method showed increase of the D110 mullite crystallite size and crystallite size distributions with small shifts to greater values with increasing firing temperature for the same type of firing (slow or fast) using the same kaolin, as well as significant differences between fast and slow firing of the same blend at different temperatures for each kaolin. The higher maximum frequency distribution of crystallite size observed at the same firing temperature using blends with M kaolin suggests a clearer crystallite growth of mullite in this blend. The agreement between thickening perpendicular to prism faces and mean crystallite sizes <D110> of mullite were not always observed because the direction perpendicular to 110 planes is not preferred for growth.

Structural and magnetic variations in Ba0.5Sr0.5Fe9Ce1Al2O19 hexaferrites at different sintering temperatures

2021 ◽  
Author(s):  
A.R. Makhdoom ◽  
Qasim Ali Ranjha ◽  
Ubaid-ur-Rehman Ghori ◽  
Muhammad Ahsan Raza ◽  
Binish Raza ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Recording Media ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray ◽  
Pure Phase ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Increasing Temperature

Abstract M-type hexaferrites has attracted researchers due to their ordinary magnetic properties and utilization as media for magnetic recording and microwave devices. In this study we have synthesized Ba0.5Sr0.5Fe9Ce1Al2O19 via conventional ceramic route. The synthesized material is treated against different temperatures and investigated structurally and magnetically by using several techniques such as X-ray diffraction, Scanning electron microscopy, and VSM respectively. Morphology of samples confirms the absence of secondary phases and uniform distribution of particles. X-ray diffraction patterns confirms the formation of pure phase of Hexaferrites. Microstructural analyses show the decrease in porosity and dislocations among sintered samples. Magnetic properties for the samples show a decrease in Ms and Mr with increasing temperature from 1225 °C to 1310 °C, while coercivity shows an increase with increasing temperature and maximum coercivity is observed at 1290 °C. The trends and occurrences can be well-linked to the structural variations and sintering effects. The results suggest that material can be used in various magnetic applications such as Recording media, and memory devices.

Dislocation densities and prevailing slip-system types determined by X-ray line profile analysis in a textured AZ31 magnesium alloy deformed at different temperatures

2013 ◽  
Vol 46 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Bertalan Jóni ◽  
Talal Al-Samman ◽  
Sandip Ghosh Chowdhury ◽  
Gábor Csiszár ◽  
Tamás Ungár
Keyword(s):  
Magnesium Alloy ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
High Angular Resolution ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities ◽  
Different Temperatures ◽  
Diffraction Patterns

Tension experiments were carried out at room temperature, 473 K and 673 K on AZ31-type extruded magnesium alloy samples. The tensile deformation has almost no effect on the typical extrusion texture at any of the investigated temperatures. X-ray diffraction patterns provided by a high-angular-resolution diffractometer were analyzed for the dislocation density and slip activity after deformation to fracture. The diffraction peaks were sorted into two groups corresponding either to the major or to the random texture components in the specimen. The two groups of reflections were evaluated simultaneously as if the two texture components were two different phases. The dislocation densities in the major texture components are found to be always larger than those in the randomly oriented grain populations. The overwhelming fraction of dislocations prevailing in the samples is found to be of 〈a〉 type, with a smaller fraction of 〈c + a〉-type dislocations. The fraction of 〈c〉-type dislocations is always obtained to be zero within experimental error.

Textured Coatings from Colloidal Suspensions of Faceted Oxide Microcrystals

1992 ◽  
Vol 286 ◽  
Author(s):  
Gregg.W. Steadman ◽  
J. R. Brewster ◽  
J. D. Budai ◽  
L. A. Boatner
Keyword(s):  
Particle Size ◽  
Colloidal Suspensions ◽  
Fiber Texture ◽  
Preferred Orientation ◽  
Morphological Properties ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Particle Size Distributions ◽  
X Ray ◽  
Flat Substrate

ABSTRACTThe morphological properties of cubic, faceted MgO microcrystals have been exploited in the formation of textured coatings. Coatings exhibiting a <100> “fiber” texture were formed by centrifugal sedimentation of colloidal suspensions onto a flat substrate. A decrease in the degree of preferred orientation in the coatings with increasing areal coverage of the particles was quantified for several particle-size distributions by using x-ray diffraction. Novel methods for the deposition of particles exhibiting an in-plane preferred orientation in addition to fiber texture have been investigated.

The Effects of Composition and Sintering Conditions on Zirconia Toughened Alumina (ZTA) Nanocomposites

2010 ◽  
Vol 93-94 ◽  
pp. 695-698 ◽  
Author(s):  
H. Esfahani ◽  
Ali Nemati ◽  
E. Salahi
Keyword(s):  
Tetragonal Zirconia ◽  
Al2o3 Nanoparticles ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Constant Composition ◽  
X Ray ◽  
Different Temperatures ◽  
Lattice Network ◽  
Diffraction Patterns ◽  
Zirconia Toughened Alumina

Zirconia Toughened Alumina (ZTA) Nanocomposites were prepared using Nano sized Zirconia (ZrO2) powders doped with 3% mol of yttria (Y2O3) nanopowders. Diffusion of α-alumina (Al2O3) nanoparticles as well as yttria into the Zirconia lattice network drives monoclinic – tetragonal martensitic transformation. Zirconia toughened alumina (ZTA) composites containing different amount of partially stabilized Zirconia (PSZ) 5, 10, 15 and 20% mol, were prepared via wet mixing and axial pressing. After sintering at different temperatures,1450, 1550 and 1650 °C, phase change in the samples were monitored. X-ray diffraction patterns showed that at constant composition, tetragonal zirconia was increased by temperature increasing due to intensification of diffuse coefficient of alumina and yttria in the system. At constant temperature, remained monoclinic zirconia was increased with Zirconia content increasing.

Structure and Magnetic Properties of Spark Plasma Sintered NdFeB

2015 ◽  
Vol 1112 ◽  
pp. 27-31
Author(s):  
Toto Sudiro ◽  
Didik Aryanto ◽  
Nenen Rusnaeni Djauhari ◽  
Citra Wara Br Sinuraya ◽  
Syahrul Humaidi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Carbon Paper ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Product ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
Effects Of Temperature ◽  
Diffraction Patterns

A spark plasma sintering technique was used to consolidate NdFeB compacts at four different temperatures as 750°C, 850°C, 950°C and 1030°C. The surface of specimens was polished to remove the carbon paper on the surface of NdFeB compacts by using SiC paper for up to #1500 in grit. The polished NdFeB compacts were then magnetized by using impulse magnetizer K-series. In this study, the effects of temperature on the structure and magnetic properties of NdFeB magnet were studied. The results show that depending on the fabrication temperature, the X-ray diffraction patterns of NdFeB compacts are distinct. This suggests that the structure of NdFeB compacts is changed with increase in fabrication temperature. Meanwhile, the remanance Br and energy product BH(max) of NdFeB magnets tend to decrease as fabrication temperature increase.

CTEAS: a graphical-user-interface-based program to determine thermal expansion from high-temperature X-ray diffraction

2013 ◽  
Vol 46 (2) ◽  
pp. 550-553 ◽  
Author(s):  
Z.A. Jones ◽  
P. Sarin ◽  
R. P. Haggerty ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensions ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Lattice Constants ◽  
Thermal Expansion Tensor ◽  
Different Temperatures ◽  
Diffraction Patterns

The coefficient of thermal expansion analysis suite (CTEAS) has been developed to calculate and visualize thermal expansion properties of crystalline materials in three dimensions. The software can be used to determine the independent terms of the second-rank thermal expansion tensor usinghklvalues, correspondingdhkllistings and lattice constants obtained from powder X-ray diffraction patterns collected at different temperatures. UsingCTEAS, a researcher can also visualize the anisotropy of this essential material property in three dimensions. In-depth understanding of the thermal expansion of crystalline materials can be a useful tool in understanding the dependence of the thermal properties of materials on temperature when correlated with the crystal structure.

X-Ray Diffraction Patterns of Oil Palm Empty Fruit Bunch Fibers with Varying Crystallinity

2015 ◽  
Vol 1087 ◽  
pp. 321-328 ◽  
Author(s):  
Fatin Afifah Ahmad Kuthi ◽  
Khairiah Haji Badri ◽  
Azlin Mohmad Azman
Keyword(s):  
Acid Hydrolysis ◽  
Oil Palm ◽  
Empty Fruit Bunch ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Before And After ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Xrd Patterns

Crystallinity of oil palm fiber from empty fruit bunch (EFB) with and without tretaments was studied by analyzing the X-ray diffraction (XRD) pattern. In this paper, we focused on the effect of acid hydrolysis onto EFB on the crystallinity of the extracted cellulose. The reaction was carried out by soaking EFB in 1% (v/v) aqueous sulfuric acid (H2SO4) at different temperatures of 120, 130 and 140°C for 1 h. The XRD patterns significantly showed changes in the 2θ peaks before and after the treatment. These changes were described in term of polymorphs type present, reflection and allomorphs of the samples. XRD peak high and XRD deconvolution methods were used to calculate and compare the percentage of crystallinity of untreated EFB (UT-EFB) and acid hydrolyzed samples (AH-EFB). Based on the calculation, increment of about 1.3 times and 1.5 times were achieved by using WAXS and XRD deconvolution methods respectively. This is due to the removal of amorphous part contributed by lignin, hemicellulose and cellulose. Fourier Transform infrared (FTIR) spectra showed the presence of similar peaks in AH-EFB and commercial microcrystalline cellulose (C-MCC) at 1427, 1315, 895 and 1022 cm-1. The micrographic features showed the acid hydrolysis had successfully took place and separated the EFB microfibrils bundles.

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