scholarly journals X-ray peak profile analysis of CoAl2O4 nanoparticles by Williamson-Hall and size-strain plot methods

2018 ◽  
Vol 4 (1) ◽  
pp. 31-40 ◽  
Author(s):  
H. Irfan ◽  
K Mohamed Racik ◽  
S. Anand
Keyword(s):  
Profile Analysis ◽  
Spinel Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Cubic Phase ◽  
Physical Parameters ◽  
Deformation Model ◽  
Uniform Deformation ◽  
X Ray ◽  
Peak Broadening

CoAl2O4nanoparticles were prepared by a sol-gel process using citric acid as chelating agent with different calcination temperatures of 600 to 900 °C. The crystalline spinel cubic phase was confirmed by X-ray diffraction results. High-resolution scanning electron microscopy (HRSEM) revealed that nanoparticles of CoAl2O4morphology showed spherical forms with a certain degree of agglomeration. The Williamson-Hall (W-H) method and size-strain method to evaluate the size of crystallites and strain in the CoAl2O4nanoparticles peak broadening were applied. Physical parameters such as strain and stress values were calculated for all XRD reflection peaks corresponding to the cubic spinel phase of CoAl2O4in the range of 20 to 70° from the modified plot shape by W-H plot assuming a uniform deformation model (UDM), uniform stress deformation model (USDM), uniform deformation energy density model (UDEDM) and by the size-strain plot method (SSP). The CoAl2O4NPs crystal size calculated on the W-H plots and the SSP method are in good agreement with the HRSEM Scherrer method.

Estimation of accurate size, lattice strain using Williamson-Hall models, SSP and TEM of Al doped ZnO nanocrystals

2018 ◽  
Vol 106 (6) ◽  
pp. 602 ◽  
Author(s):  
Milind Bodke ◽  
Umesh Gawai ◽  
Ashok Patil ◽  
Babasaheb Dole
Keyword(s):  
Energy Density ◽  
Crystallite Size ◽  
Lattice Strain ◽  
Average Crystallite Size ◽  
Physical Parameters ◽  
Deformation Model ◽  
Uniform Deformation ◽  
Zno Nanocrystals ◽  
Peak Broadening ◽  
Doped Zno

Hexagonal structure of pure and Al doped ZnO nanocrystals were synthesized by co-precipitation technique. The average crystallite size determined from XRD data using Debye Sherrer’s formula was found to be 16.8 nm for pure 19.3 nm for 4% Al Doped ZnO. High-resolution transmission electron microscopy (HR-TEM) showed single-crystal ZnO nanocrystals with nearly spherical shapes. The W-H analysis and size-strain plot were used to study the individual contributions of crystallite sizes and lattice strain “ε” on the peak broadening of pure and Al doped ZnO nanocrystals. The physical parameters namely strain, stress and anisotropic energy density were calculated considering uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM) of modified form of W-H analysis. Texture coefficient was estimated using XRD data. The average crystallite size of pure and Al doped ZnO samples estimated from W-H model. It is also revealed from the TEM the diameters of as synthesized samples are in good agreement with the W-H model analysis.

scholarly journals X-ray Diffraction Analysis and Williamson-Hall Method in USDM Model for Estimating More Accurate Values of Stress-Strain of Unit Cell and Super Cells (2 × 2 × 2) of Hydroxyapatite, Confirmed by Ultrasonic Pulse-Echo Test

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2949
Author(s):  
Marzieh Rabiei ◽  
Arvydas Palevicius ◽  
Amir Dashti ◽  
Sohrab Nasiri ◽  
Ahmad Monshi ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Ultrasonic Pulse ◽  
High Accuracy ◽  
Unit Cell ◽  
Deformation Model ◽  
X Ray Diffraction ◽  
Uniform Deformation ◽  
X Ray ◽  
Pulse Echo

Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffraction; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is performed for the validation of the novelty assumptions.

Characterization of Mn0.67Zn0.33Fe2O4 Nanoparticles Synthesized under Different pH

2017 ◽  
Vol 899 ◽  
pp. 48-53
Author(s):  
Rodrigo Uchida Ichikawa ◽  
Walter Kenji Yoshito ◽  
Margarida Juri Saeki ◽  
Willian C.A. Maranhão ◽  
Fátima Goulart ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Rietveld Method ◽  
Spinel Phase ◽  
Sem Analysis ◽  
Line Profile Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Zn Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation

Nanostructured Mn-Zn ferrites were synthesized using co-precipitation in alkaline solution with different pH. The samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analysis (TG-DTA), dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. Monophasic nanoparticles were formed when synthesized with pH 10.5. This sample was heat-treated and its XRD data was refined by the Rietveld method. Mean crystallite sizes and microstrains were determined from X-ray line profile analysis using Single-Line and Warren-Averbach methods, which revealed a mean crystallite size of approximately 10 nm and negligible microstrains. Zn content was estimated using refined cell parameters, giving a value of 33 at %, in accordance with XRF result. TG-DTA revealed that the incorporation of α-Fe2O3 occurs around 1130 °C and 1200 °C with recrystallization of the Mn-Zn ferrite spinel phase. DLS showed that mean particle size increase with temperature up to 1159 nm at 800 °C. SEM analysis showed the samples agglomerate and present similar morphology with negligible size changing when calcined between 280 °C and 800 °C. However, the sample calcined at 1200 °C presents larger agglomerates due to the sintering process.

scholarly journals Nanomaterial Host Bands Effect on the Photoluminescence Properties of Ce-Doped YAG Nanophosphor Synthesized by Sol-Gel Method

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
L. Guerbous ◽  
A. Boukerika
Keyword(s):  
Energy Levels ◽  
Sol Gel ◽  
Yellow Emission ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Annealing Temperatures

Cerium trivalent (Ce3+) doped YAG nano-sized phosphors have been successfully synthesized by sol-gel method using different annealing temperatures. The samples have been characterized by X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, and steady photoluminescence (PL) spectroscopy. X-ray diffraction analysis indicates that the pure cubic phase YAG was formed and strongly depends on the cerium content and the annealing temperature. It was found that the grain size ranges from 30 to 58 nm depending on the calcination temperature. The YAG: Ce nanophosphors showed intense, green-yellow emission, corresponding to Ce3+5d1→2F5/2,2F7/2transitions and its photoluminescence excitation spectrum contains the two Ce3+4f1→5d1, 5d2bands. The crystal filed splitting energy levels positions 5d1and 5d2and the emission transitions blue shift with annealing temperatures have been discussed. It was found that the Ce3+4f1ground state position relative to valence band maximum of YAG host nanomaterial decreases with increasing the temperature.

Preparation of LaFeO3 particles by sol-gel technology

1998 ◽  
Vol 13 (2) ◽  
pp. 451-456 ◽  
Author(s):  
C. Vázquez-Vázquez ◽  
P. Kögerler ◽  
M. A. López-Quintela ◽  
R. D. Sánchez ◽  
J. Rivas
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Infrared Spectroscopy ◽  
Sol Gel ◽  
Diffraction Peak ◽  
Gel Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Component ◽  
Peak Broadening

The study of submicroscopic particles in already known systems has resulted in a renewed interest due to the large differences found in their properties when the particle size is reduced, and because of possible new technological applications. In this work we report the preparation of LaFeO3 particles by the sol-gel route, starting from a solution of the corresponding metallic nitrates and using urea as gelificant agent. Gels were decomposed at 200 °C and calcined 3 h at several temperatures, T, in the range 250–1000 °C. The samples were structurally characterized by x-ray diffraction (XRD) showing that the orthoferrite crystallizes at T as low as 315 °C. From the x-ray diffraction peak broadening, the particle size was determined. The size increases from 60 to 300 nm as the calcination T increases. Infrared spectroscopy was used to characterize gels and calcined samples. From these studies a mechanism for the gel formation is proposed. Study of the magnetic properties of LaFeO3 particles shows the presence of a ferromagnetic component which diminishes as the calcination temperature increases, vanishing at T = 1000 °C.

Performance Effect of ZnAl2O4 - SiO2 Thin Film for Wireless Patch Antenna Application

2014 ◽  
Vol 28 ◽  
pp. 141-150 ◽  
Author(s):  
Mohd Syafiq Zulfakar ◽  
Huda Abdullah ◽  
Mohammad Tariqul Islam ◽  
Wan Nasarudin Wan Jalal ◽  
Zalita Zainuddin ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Patch Antenna ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Cubic Phase ◽  
Frequency Range ◽  
Performance Effect ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Polycrystalline of (1-x)ZnAl2O4 – xSiO2 compound with compositions of x = 0.00, 0.05, 0.10, 0.15, 0.20 and 0.25 have been prepared using sol-gel method. Structural properties was investigated by atomic force microscopy (AFM) and x-ray diffractometer (XRD). The AFM images analysis showed that the surface roughness of the highest composition had rougher surface compared with other samples. XRD measurement indicated that the crystallite size also increased with average crystallite size around 18 nm with cubic phase had been found. The dielectric permittivity value were measured with frequency range of 1 Hz to 1 MHz. It is showed that the dielectric value decreased as the freqeuncy was applied to the samples. The performance of the patch antenna showed that the antenna resonated at 3.30 GHz and give-13.87 dB with frequency range about 2 – 4 GHz.

scholarly journals Structural, Optical, and Catalytic Properties of MgCr2O4 Spinel-Type Nanostructures Synthesized by Sol–Gel Auto-Combustion Method

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1476
Author(s):  
Vasyl Mykhailovych ◽  
Andrii Kanak ◽  
Ştefana Cojocaru ◽  
Elena-Daniela Chitoiu-Arsene ◽  
Mircea Nicolae Palamaru ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Catalytic Properties ◽  
Spinel Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Temperature Treatment ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
X Ray ◽  
Auto Combustion

Spinel chromite nanoparticles are prospective candidates for a variety of applications from catalysis to depollution. In this work, we used a sol–gel auto-combustion method to synthesize spinel-type MgCr2O4 nanoparticles by using fructose (FS), tartaric acid (TA), and hexamethylenetetramine (HMTA) as chelating/fuel agents. The optimal temperature treatment for the formation of impurity-free MgCr2O4 nanostructures was found to range from 500 to 750 °C. Fourier transform infrared (FTIR) spectroscopy was used to determine the lattice vibrations of the corresponding chemical bonds from octahedral and tetrahedral positions, and the optical band gap was calculated from UV–VIS spectrophotometry. The stabilization of the spinel phase was proved by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis. From field-emission scanning electron microscopy (FE-SEM), we found that the size of the constituent particles ranged from 10 to 40 nm. The catalytic activity of the as-prepared MgCr2O4 nanocrystals synthesized by using tartaric acid as a chelating/fuel agent was tested on the decomposition of hydrogen peroxide. In particular, we found that the nature of the chelating/fuel agent as well as the energy released during the auto-combustion played an important role on the structural, optical, and catalytic properties of MgCr2O4 nanoparticles obtained by this synthetic route.

Structural and Electrical Conductivity Studies in Nickel Ferrite Nano-Particles

2013 ◽  
Vol 209 ◽  
pp. 177-181 ◽  
Author(s):  
Ram S. Barkule ◽  
D.V. Kurmude ◽  
A.V. Raut ◽  
N.N. Waghule ◽  
K.M. Jadhav ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Nickel Ferrite ◽  
Sol Gel ◽  
Chelating Agent ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

Abstract: The magnetic nano-particles of nickel ferrite were synthesized successfully by sol-gel auto-combustion method using high purity metal nitrates and citric acid as chelating agent. The as prepared powder of nickel ferrite was sintered at 5500C for 5 hr to obtain good crystalline phase and was used for further study. The X-ray diffraction technique was employed to confirm the single phase formation of nickel ferrite nano-particles. The X-ray diffraction pattern shows the Bragg’s peak which belongs to cubic spinel structure. The values of lattice constant, X-ray density, oxygen parameter and radii of tetrahedral and octahedral sites were calculated from XRD data. The average crystallite size was estimated using Scherrer’s formula and found to be 6 nm. The temperature dependence of the electrical conductivity plot shows the kink, which can be attributed to ferromagnetic-paramagnetic transition. The activation energy obtained from resistivity plots in paramagnetic region is found to be more than that in ferrimagnetic region. The conduction mechanism in these nickel ferrite nano-particles has been discussed on the basis of hopping of electrons.

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