scholarly journals Solvent-deficient synthesis of nanocrystalline Ba0.5Sr0.5Co0.8Fe0.2O3-δ powder

2018 ◽  
Vol 12 (4) ◽  
pp. 342-349 ◽  
Author(s):  
Sasa Zeljkovic ◽  
Jin Miyawaki ◽  
Dragoljub Vrankovic ◽  
Elena Tervoort ◽  
Roland Hauert ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Ammonium Bicarbonate ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Rapid Synthesis ◽  
X Ray ◽  
Metal Nitrates

Nanocrystalline Ba0.5Sr0.5Co0.8Fe0.2O3-? powders were prepared by a cost-effective solvent-deficient method using metal nitrates and ammonium bicarbonate as precursors. X-ray diffraction (XRD), specific surface determination (BET), thermal analyses (TG-DTA-DSC), dynamic light scattering (DLS) and scanning electron microscopy (SEM) were used to examine the effects of the calcination temperature on the Ba0.5Sr0.5Co0.8Fe0.2O3-? (BSCF) formation. XRD analysis showed that a cubic Ba0.5Sr0.5Co0.8Fe0.2O3-? was obtained after heating for 1 h at 1000?C. BSCF nanocrystals with a diameter of about 25 nm were obtained. On the other hand, the sample mass was stabilized at 915?C as recorded by thermogravimetric analysis (TG), indicating a formation of the complex BSCF oxide already at this temperature. The phase transformations during the synthesis of BSCF oxide are defined and confirmed with the note on the instability of the cubic phase. Using the four-point DC measurements between ?73?C and 127?C, the band gap of 0.84 eV was determined. The solvent-deficient method used in this study to synthesize Ba0.5Sr0.5Co0.8Fe0.2O3-? showed distinct advantages in comparison with other synthesis techniques considering simplicity, rapid synthesis, and quality of the produced nanocrystals.

Development of Ternary Concrete Utilizing Agricultural Waste Material

2022 ◽  
Author(s):  
Sunita Kumari ◽  
Dhirendra Singhal ◽  
Rinku Walia ◽  
Ajay Rathee
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Agricultural Waste ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Concrete Mix ◽  
Maize Cob

Abstract The present project proposes to utilize rice husk and maize cob husk ash in the cement to mitigate the adverse impact of cement on environment and to enhance the disposal of waste in a sustainable manner. Ternary concrete / MR concrete was prepared by using rise husk and maize cob ash with cement. For the present project, five concrete mixes MR-0 (Control mix), MR-1 (Rice husk ash 10% and MR-2.5%), MR-2 (Rice husk ash 10% and MR-5%), MR-3 (Rice husk ash 10% and MR-2.5%), MR-4 (Rice husk ash 10% and MR-2.5%) were prepared. M35 concrete mix was designed as per IS 10262:2009 for low slump values 0-25mm. The purpose is to find the optimum replacement level of cement in M35 grade ternary concrete for I – Shaped paver blocks.In order to study the effects of these additions, micro-structural and structural properties test of concretes have been conducted. The crystalline properties of control mix and modified concrete are analyzed by Fourier Transform Infrared Spectroscope (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results indicated that 10% Rice husk ash and 5% maize cob ash replaced with cement produce a desirable quality of ternary concrete mix having good compressive strength. The results of SEM analysis indicated that the morphology of both concrete were different, showing porous structure at 7 days age and become unsymmetrical with the addition of ashes. After 28 day age, the control mix contained more quantity of ettringite and became denser than ternary concrete. XRD analysis revealed the presence of portlandite in large quantity in controlled mix concrete while MR concrete had the partially hydrated particle of alite.

scholarly journals High-pressure and -temperature spinning capillary cell for in situ synchrotron X-ray powder diffraction

2019 ◽  
Vol 26 (4) ◽  
pp. 1238-1244 ◽  
Author(s):  
Edmundo Fraga ◽  
Jesus D. Zea-Garcia ◽  
Armando Yáñez ◽  
Angeles G. De la Torre ◽  
Ana Cuesta ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Cost Effective ◽  
Oil Well ◽  
X Ray Diffraction ◽  
High Pressure And Temperature ◽  
X Ray ◽  
Quantitative Analyses ◽  
Well Cement

In situ research of materials under moderate pressures (hundreds of bar) is essential in many scientific fields. These range from gas sorption to chemical and biological processes. One industrially important discipline is the hydration of oil well cements. Existing capillary cells in this pressure range are static as they are easy to design and operate. This is convenient for the study of single-phase materials; however, powder diffraction quantitative analyses for multiphase systems cannot be performed accurately as a good powder average cannot be attained. Here, the design, construction and commissioning of a cost-effective spinning capillary cell for in situ powder X-ray diffraction is reported, for pressures currently up to 200 bar. The design addresses the importance of reducing the stress on the capillary by mechanically synchronizing the applied rotation power and alignment on both sides of the capillary while allowing the displacement of the supports needed to accommodate different capillaries sizes and to insert the sample within the tube. This cell can be utilized for multiple purposes allowing the introduction of gas or liquid from both ends of the capillary. The commissioning is reported for the hydration of a commercial oil well cement at 150 bar and 150°C. The quality of the resulting powder diffraction data has allowed in situ Rietveld quantitative phase analyses for a hydrating cement containing seven crystalline phases.

Phase Evolution and Physical Properties of (1-x)BZT-xBFN Ceramic System

2008 ◽  
Vol 55-57 ◽  
pp. 53-56 ◽  
Author(s):  
H. Maimon ◽  
Sukum Eitssayeam ◽  
Uraiwan Intatha ◽  
Tawee Tunkasiri ◽  
G. Satittada
Keyword(s):  
Physical Properties ◽  
Physical And Mechanical Properties ◽  
Phase Evolution ◽  
Xrd Analysis ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Ceramic System ◽  
Solid State Reaction Technique ◽  
Temperature Changes ◽  
X Ray

Phase evolution and physical properties of (1-x)BZT–xBFN ceramic system were investigated to find the optimum condition for electronic applications. (1-x)BZT–xBFN powders were prepared by solid state reaction technique varying x from 0.2 to 0.8 and various sintering temperatures from 1350 °C to 1450 °C. Phase formation was investigated by X-ray diffraction technique. The XRD analysis demonstrated that with increasing BFN content in (1−x)BZT–xBFN, the structural change occurred from the tetragonal to the cubic phase at room temperature. Changes in the physical and mechanical properties were then related to this structural transformation depending on the BFN content.

SYNTHESIS AND CHARACTERIZATION OF SPHERE-LIKE ZnS NANOCRYSTALS BY THERMOLYSIS OF A NEW COMPLEX PRECURSOR

2010 ◽  
Vol 24 (19) ◽  
pp. 2091-2099 ◽  
Author(s):  
JIANJUN ZHANG ◽  
JUNHONG DUAN
Keyword(s):  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Inorganic Compounds ◽  
Xrd Analysis ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Stream ◽  
Zns Nanocrystals

In this paper, the preparation and optical properties of sphere-like ZnS nanocrystals are reported. Pure and uniform cubic-phase sphere-like ZnS nanocrystals with grain sizes of 30–40 nm were synthesized by thermolysis of a new precursor complex ( enH 2)0.5[ Zn ( en )3]( SCN )3 (en = ethylenediamine) in nitrogen stream at 800°C. The as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), respectively. The XRD analysis reveals the phase of ZnS with cubic zinc blende. UV-Vis and photoluminescence spectra (PL) were utilized to investigate the optical properties of sphere-like ZnS nanocrystals. By testing on UV-Vis spectra, it is concluded that the limiting wavelength of the ZnS nanocrystals is 320 nm and the band gap is 3.88 eV. In room temperature PL spectra, one strong emission peak centered at 322 nm is discovered, which could be attributed to the band to band transitions. The above-mentioned results showed that the thermolysis method is preferable for synthesizing high-quality sphere-like ZnS nanocrystals. The synthesized precursor could be used as morphological templates to prepare nanostructure inorganic compounds.

scholarly journals BIOCERAMIC COMPOSITE: HEN’S EGGSHELL CHARACTERIZATION AND MAIN APPLICATIONS

2018 ◽  
Vol 4 (1) ◽  
pp. 9-20
Author(s):  
Jenniffer Syreetta de Oliveira Spelta ◽  
André Gustavo de Sousa Galdino
Keyword(s):  
Thermal Analyses ◽  
Xrd Analysis ◽  
Raw Material ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Food Industries ◽  
Technological Potential ◽  
Decomposition Of Organic Matter ◽  
Chicken Eggshell

The chicken eggshell is a bioceramic composite which constitutes a solid waste material whose final disposal is complex and expensive. Brazil generates significant amounts of eggshell residue. This work aimed to characterize the eggshells of white, red and backyard hens and indicate their technological potential as raw material for ceramic products manufacturing. The eggshells were crushed, ground, sifted in a ABNT number 80 sieve and subsequently analyzed by X-rays fluorescence (XRF), X-ray diffraction (XRD) and thermal analyses (DTA and TGA). Through XRF it was observed that the main constituent of eggshell is calcium oxide (CaO), with different percentages between the eggshell types. XRD analysis indicated that the chicken eggshells used in this work are mainly composed of CaCO3. DTA and TGA demonstrated that the thermal decomposition of the chicken eggshells occurs in three events: water removal; decomposition of organic matter; and decomposition of CaCO3 in CaO and CO2. By reviewing the literature, it was verified that chicken eggshells have important applications since they can be used in biomedicine, civil construction, food industries and as soil nutrients. As a result, it is possible to conclude that the chicken eggshell is rich in CaCO3 and can be easily calcined to obtain CaO.

Structural and Morphologies of (1-x)BaTiO3-xBaFe0.5Nb0.5O3 Solid Solution

2008 ◽  
Vol 55-57 ◽  
pp. 137-140 ◽  
Author(s):  
Sukum Eitssayeam
Keyword(s):  
Solid Solution ◽  
Structural Change ◽  
Solid State ◽  
Room Temperature ◽  
Xrd Analysis ◽  
Dielectric Measurement ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Temperature Changes ◽  
X Ray

The structural and physical properties of(1−x)BaTiO3 –xBaFe0.5Nb0.5O3 ceramics system were investigated as a function of the BaFe0.5Nb0.5O3 content by X-ray diffraction (XRD) and dielectric measurement technique. Studies were performed on the samples prepared by solid state reaction for x = 0, 0.2, 0.4 and 0.6. The XRD analysis demonstrated that with increasing BFN content in (1−x)BT–xBFN, the structural change occurred from the tetragonal to the cubic phase at room temperature. Changes in the morphology were then related to these structural depending on the BFN content.

Utilizing Iron Tailing, Sludge and Fly Ash to Prepare Ceramsites

2020 ◽  
Vol 13 (1) ◽  
pp. 16-25
Author(s):  
Zi Wang ◽  
Hongjun Chen ◽  
Chunhu Yu ◽  
Zeyang Xue ◽  
Pengxiang Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Duration Time

Background: The deposits of iron tailing will pose a great risk of environmental pollution and serious landscape impact which will affect the quality of life of humans. Therefore, it is urgent to utilize iron tailing to produce valuable products. Methods: The tailing ceramsites were analysed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The roles of the tailing content, sintering temperature and duration time in the performance of the tailing ceramsites were analysed and the optimal sintering parameters were determined. Results: The bulk density, apparent density and cylinder compressive strength of the tailing ceramsites increase considerably with the increase of the sintering temperature and duration time. The cylinder compressive strength of the tailing ceramsites increases with increasing the tailing content. The optimal sintering parameter is 1100°C for 40 min. The cylinder compressive strength of the tailing ceramsites obtained at 1100°C for 40 min reaches 10.1 MPa. XRD analysis shows that the tailing ceramsites mainly consist of CaSiO3, Al2SiO5, MgSiO3, Ca7Si2P2O16, CaAl2Si2O8, Ca2Fe2O5 and SiO2 phases when the sintering temperature and duration time were increased to 1100°C and 40 min, respectively. Conclusion: The tailing ceramsites were obtained from iron tailing, sludge and fly ash as the raw materials at 1100°C for 40 min. The obtained ceramsites exhibited high mechanical performance.

Ambient Condition Synthesis of Ag Submicron Crystallites from AgNO3, H2O2 and NH3•H2O

2011 ◽  
Vol 391-392 ◽  
pp. 1392-1395
Author(s):  
Jing Li ◽  
Yong Cai Zhang
Keyword(s):  
Aqueous Solutions ◽  
Atmospheric Pressure ◽  
Cost Effective ◽  
Cubic Phase ◽  
Present System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cost Effective Method ◽  
Diffraction Patterns ◽  
Microscopy Images

A simple and cost-effective method based on the reduction of AgNO3 by H2O2 (5 vol.%) in 2.5–5 vol.% NH3•H2O aqueous solutions at room temperature and under atmospheric pressure was developed for the synthesis of Ag submicron crystallites. X-ray diffraction patterns demonstrated that the resultant products were pure cubic phase Ag powders. Field emission scanning electronic microscopy images showed that the Ag powders synthesized in 2.5 and 5 vol.% NH3•H2O aqueous solutions comprised submicron crystallites with the sizes of about 355–580 and 200–650 nm, respectively. Besides, the possible formation mechanism of Ag powders in the present system was also proposed.

scholarly journals Growth of the Electrodeposited NiX2 (X= Te, Se) Thin Films

2020 ◽  
pp. 55-69
Author(s):  
T. Joseph Sahaya Anand ◽  
Rajes K. M. Rajan ◽  
Md Radzai Said ◽  
Lau Kok Tee
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Compositional Analysis ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Potential Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
P Type

Thin films of nickel chalcogenide, NiX2 (X= Te, Se) have been electrosynthesized on indium-tin-oxide (ITO) coated glass substrates. The films were characterized for their structural, morphological and compositional characteristics. Consisting of transition metals and chalcogenides (S, Se and Te), they show promising solar absorbent properties such as semiconducting band gap, well adhesion to substrate and good conversion with better cost-effective. Cyclic voltammetry experiments have been done prior to electrodeposition in order to get the electrodeposition potential range where the observable reduction range is between -0.9-(-1.1) V. Their optical and semiconducting parameters were also analysed in order to determine the suitability of the thin films for photoelectrochemical (PEC) / solar cell applications. Structural analysis via X-ray diffraction (XRD) analysis reveals that the films are polycrystalline in nature. Scanning electron microscope (SEM) studies reveals that the films were adherent to the substrate with uniform and pin-hole free. Compositional analysis via energy dispersive X-ray (EDX) technique confirms the presence of Ni, Te, and Se elements in the films. The optical studies show that the films are of direct bandgap. Results on the semiconductor parameters analysis of the films showed that the nature of the Mott-Schottky plots indicates that the films obtained are of p-type material.

scholarly journals Enhancement of Visible Upconversion Emission in Y2O3:Er3+-Yb3+by Addition of Thiourea and LiOH in the Phosphor Synthesis

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Eder Resendiz-L ◽  
Luis Armando Diaz-Torres ◽  
Luis Octavio Meza Espinoza ◽  
Claramaria Rodríguez-González ◽  
Pedro Salas
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Xrd Analysis ◽  
Upconversion Emission ◽  
Synthesis Process ◽  
Cubic Phase ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray

Spherical like Y2O3nanostructures doped with Er3+and Yb3+ions have been synthesized by a facile hydrothermal method. The samples were prepared by using different precipitant agents in the synthesis process. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectroscopy. Effects of the precipitant agents on structural, morphological, and photoluminescence properties of Y2O3:Er3+-Yb3+are studied and discussed. XRD analysis indicates that all samples, prepared with different precipitant agents, present the same cubic phase. Electron microscopy measurements show regular spherical shapes with size diameter depending on precipitant agent. Photoluminescence reveals that the samples have strong green (563 nm) and red (660 nm) emissions corresponding to4S3/2 → 4I15/2and4F9/2 → 4I15/2transitions of Er3+ions, respectively. The nanophosphors prepared with both Thiourea and Lithium Hydroxide exhibit the stronger visible upconversion luminescence under 980 nm diode laser excitation.

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