Morphology and microstructural properties of TiO2 nanopowders doped with trivalent Al and Ga cations

2000 ◽  
Vol 15 (10) ◽  
pp. 2080-2086 ◽  
Author(s):  
L. E. Depero ◽  
A. Marino ◽  
B. Allieri ◽  
E. Bontempi ◽  
L. Sangaletti ◽  
...  
Keyword(s):  
Average Crystallite Size ◽  
Microstructural Properties ◽  
Crystallite Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructural Parameters ◽  
Different Temperatures ◽  
Trivalent Cations ◽  
Tio2 Nanopowders ◽  
Xrd Patterns

The effects of doping on the morphological and microstructural properties of TiO2 nanopowders produced by laser pyrolysis were investigated mainly by x-ray diffraction (XRD) and electron microscopy. Samples of TiO2 powders were prepared by doping with different trivalent cations (Al and Ga). The powders were calcined at different temperatures in the range 400–1000 °C for 18 h, as well as at constant T = 700 °C up to 160 h. After each thermal treatment, XRD patterns were collected. The analysis of XRD patterns allowed us to estimate the microstrains and average crystallite size and to observe the evolution of the microstructural parameters with temperature. Both Al and Ga inhibited the crystallite growth of TiO2 anatase and the rutile phases, this effect being larger in the Al-doped powders.

STRUCTURE AND MAGNETIC PROPERTIES OF MECHANICAL ALLOYED Mn-15at.%Al

2013 ◽  
Vol 12 (01) ◽  
pp. 1350006
Author(s):  
AHMED E. HANNORA ◽  
FARIED F. HANNA ◽  
LOTFY K. MAREI
Keyword(s):  
Thermal Analysis ◽  
Room Temperature ◽  
Average Crystallite Size ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Milled Sample ◽  
Powder Samples ◽  
Xrd Patterns ◽  
Method Analysis

Mechanical alloying (MA) method has been used to produce nanocrystallite Mn -15at.% Al alloy. X-ray diffraction (XRD) patterns for the as-milled elemental α- Mn and aluminum powder samples show a mixture of α + β- MnAl phases after 20 h of milling and changes to a dominant β- MnAl phase structure after 50 h. An average crystallite size of 40 nm was determined from Hall–Williamson method analysis after 5 h of milling. Moreover, the thermal analysis results using differential thermal analysis (DTA), suggested a possible phase transformation after 20 h of milling. Isothermal treatments are carried in the temperature range of 450°C to 1000°C. Room-temperature vibrating sample magnetometer (VSM) measurements of the hysteretic response revealed that the saturation magnetization Bs and coercivity Hc for 10 h ball milled sample are ~ 2.1 emu/g and ~ 92 Oe, respectively.

scholarly journals FTIR and Optical Properties of NiO Doped Cr2O3 Nanopar-ticles Synthesis by Hydrothermal Method

2018 ◽  
Vol 29 (1) ◽  
pp. 168
Author(s):  
Tunis Balassim Hassan
Keyword(s):  
Optical Band Gap ◽  
Average Crystallite Size ◽  
Structural Behavior ◽  
X Ray Diffraction ◽  
Nanopar Ticles ◽  
Hydrothermal Technique ◽  
X Ray ◽  
Cr2o3 Nanoparticles ◽  
Xrd Patterns ◽  
Scanning Electron

Pure and Nickel oxide doped chromium (III) oxide (Cr2O3) nanoparticals are synthesized by hydrothermal technique. The effect of dopant Ni concentration on the structural behavior of Cr2O3 nanoparticles was examined by X-ray diffraction. The average crystallite size of the synthesized nanoparticles was measured from XRD patterns using Scherrer equation and was decreased from 22nm to 12.9 nm with the increasing Nio concentration in Cr2O3 from (0, 0.01, 0.06, and 0.10). Morphologies and compositional elements of the synthesized nanoparticles were observed by the field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy, respectively. The optical property of the samples was measured by ultraviolet - visible (UV-Vis.) absorption spectroscopy. The observed optical band gap value ranges from 2.3eV to 2.5eV for Ni doped nanoparticles

Interfacial Reactions Between Ain Substrate And 4-A Family Elements

1995 ◽  
Vol 398 ◽  
Author(s):  
Yong Du ◽  
Xiangjun He ◽  
Kun Tao
Keyword(s):  
Direct Product ◽  
Vapour Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Interfacial Reactions ◽  
Physical Vapour Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Diffraction Peaks ◽  
Xrd Patterns

ABSTRACTInterfacial reactions between A1N substrate and 4A-family elements including Ti, Zr and Hf were studied. The samples were prepared by Physical Vapour Deposition and annealed at different temperatures from 200°C to 800°C. X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) were employed to detect the compounds formed at the interfaces between them. For Ti/AIN system, when the samples were annealed from 600°C to 800°C for 1 hour, it was found from XRD patterns that TiAl3, TiN, and Ti4N3.x including Ti2N were formed at Ti/AIN interface. With the temperature increasing, the intensities of Ti, TiN(200), Ti2N and Ti4N3.x diffraction peaks decreased while that of TiAl3 and TiN(111) increased. For Zr/AlN system, it was found that the reactions between Zr and AlN resulted in the formation of Al3Zr at about 300°C and Al2Zr at about 500°C. According to RBS spectra, it can be assumed that Al3Zr was the direct product by the reaction between AlN and Zr and Al2Zr was formed by the reaction between Al3Zr and Zr. For Hf/AlN system, however, even the sample was annealed at 800°C, no compound resulted from interfacial reactions was detected.

Magnetic Properties of Mg0.4Ca0.6Fe2O4 Nanoparticles Synthesized by Sol-Gel Method for Hyperthermia Treatment

2014 ◽  
Vol 631 ◽  
pp. 193-197
Author(s):  
A.M. Escamilla-Pérez ◽  
D.A. Cortés-Hernández ◽  
J.M. Almanza-Robles ◽  
D. Mantovani ◽  
P. Chevallier
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Different Temperatures ◽  
Xrd Patterns

Powders of Mg0.4Ca0.6Fe2O4were prepared by sol-gel using ethylene glycol and Mg, Ca and Fe nitrates as starting materials. Those powders were heat treated at different temperatures (300, 400, 500 and 600 °C) for 30 min. The materials obtained were characterized by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The Ca-Mg ferrite with the most appropriate magnetic properties was further analyzed by transmission electron microscopy (TEM). The heating capability of the nanoferrites was also tested via magnetic induction. The XRD patterns of these Ca-Mg ferrites showed a cubic inverse spinel structure. Furthermore, neither traces of hematite nor orthorhombic Ca ferrite phases were detected. Moreover, all the Ca-Mg ferrites are superparamagnetic and the particle size distribution of these Ca-Mg magnetic nanoparticles exhibits an average diameter within the range of 10-14 nm. The needed temperature for hyperthermia treatment was achieved at around 12 min.

scholarly journals Investigation on the Particle Growth of Rutile TiO2 Suppressed by Manganese

2018 ◽  
Vol 221 ◽  
pp. 01005
Author(s):  
Aripin ◽  
Edvin Priatna ◽  
Nundang Busaeri ◽  
Rudi Priyadi ◽  
I Nyoman Sudiana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Scanning Electron Microscopy ◽  
Particle Growth ◽  
Crystallite Growth ◽  
X Ray Diffraction ◽  
Rutile Tio2 ◽  
X Ray ◽  
Xrd Patterns ◽  
Scanning Electron

In this paper, we present the results of an investigation on the crystallite growth of rutile TiO2 and the formation of Mn–O–Ti bonds in a TiO2/manganese composition. The effects of manganese loading from 20 wt% to 80 wt%, into TiO2 at a temperature of 1200°C on the structural properties, have been studied. The material’sproperties have been characterized on the basis of the experimental data obtained using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). It has been found that an increase of the loading by manganese up to 80 wt% leads to a decrease of the rutile crystallites size and an increase of the amount of Mn–O–Ti bonds. The analysis based on the interpretation of both XRD patterns and FTIR spectrum allows one to explain the reduction of the crystallite size of rutile TiO2 by an increase of the manganese loading.

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.

Effects of Minor Elements Additions to the Nanocrystalline FeAl Alloy Produced by Powder Metallurgy

2020 ◽  
Vol 1005 ◽  
pp. 3-9
Author(s):  
Zineb Hamlati ◽  
Fadhéla Otmane ◽  
H. Mechri ◽  
W. Laslouni ◽  
Mohammed Azzaz
Keyword(s):  
Mechanical Alloying ◽  
Room Temperature ◽  
Average Crystallite Size ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Feal Alloy ◽  
Materials Properties ◽  
X Ray ◽  
Rotating Speed ◽  
Minor Elements

Mechanical alloying has recently attracted considerable attention as researchers try to improve materials properties. The process can be performed at room temperature and homogeneous alloys can be produced. In this work Fe–28 wt. % Al; Fe–26 wt. % Al–2 wt. % Sn and Fe–26 wt. % Al–2 wt. % V alloys were synthesized by mechanical alloying to investigate the effects of tin and vanadium additions on the structural and microstructural properties of Nanocrystalline FeAl Alloy. Fe72Al28, Fe72Al26Sn2 and Fe72Al26Sn2 were ball milled for 30 h under argon atmosphere using a rotating speed of 200 rpm with 15 min pause time after every 15 min running time. The structural and microstructural properties of the ball milled powders were analyzed using X-ray diffraction (DRX) and Mössbauer spectroscopy techniques. The final powders are characterized by an average crystallite size of 10 nm for the Fe72Al28 alloy, 6 nm for the Fe72Al26Sn2 alloy and 19 nm for the Fe72Al26V2, accompanied by the introduction of a lattice strain of order of 1.55 %, 0.78 % and 0.80% respectively. The Mossbauer study of the Fe72Al26V2 samples showed doublet with isomer shift IS= 0.17 mm/s and three magnetically split sextet.

Property Comparison of CuInSi Films Prepared by Multilayer Synthesized and Magnetron Co-Sputtering

2011 ◽  
Vol 110-116 ◽  
pp. 3755-3761
Author(s):  
Jian Sheng Xie ◽  
Jin Hua Li ◽  
Ping Luan
Keyword(s):  
Grain Size ◽  
Film Surface ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Absorption Studies ◽  
Nanocomposite Thin Films ◽  
Different Temperatures ◽  
Xrd Patterns

Using magnetron sputtering technology, the CuInSi nanocomposite thin films were prepared by magnetron co-sputtering method and multilayer synthesized method respectively,and followed by annealing in N2 atmosphere at different temperatures. The structure of CuInSi nanocomposite films were detected by X-ray diffraction (XRD); X-ray diffraction studies of the annealed films indicate the presence of CuInSi, the peak of main crystal phase is at about 2θ=42.308°,meanwhile,there are In2O3 peak and other peaks in the XRD patterns of films. The morphology of the film surface was studied by SEM. The SEM images show that the crystalline of the film prepared by multilayer synthesized method was granulated, But the crystalline of the film prepared by magnetron co-sputtering with needle shape. The grain size is a few hundred angstroms. The band gap has been estimated from the optical absorption studies and found to be about 1.40 eV for the sample by magnetron co-sputtering, and 1.45eV for the sample by multilayer synthesized, but all changes with the purity of CuInSi.

Epitaxial and Conductive RuO2 Thin Films Grown on MgO and LaAlO3 by MOCVD

1998 ◽  
Vol 541 ◽  
Author(s):  
P. Lu ◽  
S. He ◽  
F. X. Li ◽  
Q. X. Jia
Keyword(s):  
Thin Films ◽  
Orientation Relationship ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractConductive RuO2 thin films have been grown epitaxially on (100) MgO and (100) LaAlO3 substrates by metal-organic chemical vapor deposition(MOCVD) at different temperatures. The microstructural properties of the RuO2 films have been studied using x-ray diffraction and scanning electron microscopy. Different growth and microstructure properties were observed for the films deposited on the two substrates. The films on MgO are epitaxial at deposition temperatures as low as 350°C, and consist of two variants with an orientation relationship given by (110) RuO2 /(100) MgO and [001] RuO2//[011]MgO. The films on LaAlO3, on the other hand, are epitaxial only at deposition temperatures of 600°C and above, and contain four variants with an orientation relationship given by (200)RuO2//(100)LaAlO3 and [011] RuO2//[011] LaAlO3. The observed microstructures of epitaxially grown films can be explained based on geometric considerations for the films and substrates.

scholarly journals Effect of Synthesis and Sintering Temperatures on K0.5Na0.5NbO3 Lead-Free Piezoelectric Ceramics By Microwave Heating

2021 ◽  
Author(s):  
Anggel Lagunas ◽  
Maria Guadalupe Navarro-Rojero ◽  
Maria Dolores Salvador ◽  
Jose Manuel Catalá ◽  
Amparo Borrell
Keyword(s):  
Intermediate Phase ◽  
Piezoelectric Materials ◽  
Microwave Sintering ◽  
Single Mode ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Xrd Patterns

Abstract Powders of K0.5Na0.5NbO3 lead-free piezoelectric ceramics were successfully synthesized via conventional and microwave-assisted heating. A single-mode microwave equipment was used to perform the synthesis following the mixed oxide route and then sintering at different temperatures. The synthesized powders obtained and then sintered by microwave and conventional methods were evaluated by thermogravimetry analysis, X-ray diffraction (XRD), and field emission scanning electron microscopy. Microwave synthesis processing for 10 minutes at 650 ºC using a heating rate of 30 ºC/min promotes the formation of 2 K0.5Na0.5NbO3 nanoparticles. Perovskite structure formed during calcination shows the coexistence of tetragonal-orthorhombic geometry according to XRD patterns. The microwave-obtained particles are consistent with the theoretical stoichiometry. Particle size increases as the reaction temperature is increased from 650 ºC to 800 ºC. An intermediate phase (K,Na)2Nb4O11 is formed in the entire range of synthesis temperatures studied. The samples obtained by microwave sintering show a structure similar to the samples sintered by the conventional method. However, the porosity observed in the microstructure of the microwave-sintered piezoelectric materials affects the density of the material, and these defects cause a decrease in the dielectric values.

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