scholarly journals Nitridated Ca2NaMg2V3O12: Eu3+ Vanadate Garnet Phosphor-in-Glass

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2996
Author(s):  
Damian Pasinski ◽  
Jerzy Sokolnicki
Keyword(s):  
Thermal Stability ◽  
Single Phase ◽  
Low Energy ◽  
Color Temperature ◽  
Garnet Structure ◽  
Air Atmosphere ◽  
Ammonia Atmosphere ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Emission Quantum Yield

In this study, Ca2NaMg2V3O12 coordination compound undoped and doped with Eu3+ obtained in the air and ammonia atmosphere by solid-state reaction was investigated. Ca2NaMg2V3O12: Eu3+ obtained in the ammonia atmosphere was then investigated as a phosphor-in-glass (PiG). Annealed Ca2NaMg2V3O12: Eu3+ phosphor forms a single phase with the cubic garnet structure and Ia3d space group. Nitridation in ammonia causes a widening of a VO43− group emission band on the low energy side and it red-shifts by 20 nm. The emission of Eu3+ is extended as compared to the non-nitridated phosphor. Ca2NaMg2V3O12: Eu3+ after nitridation shows higher emission quantum yield (QY): 49 vs. 45 and lower correlated color temperature (CCT) and 4179 vs. 4998 as compared to phosphor without nitridation. The QY for PiG is 55. The thermal stability of nitridated phosphors is superior to phosphor obtained in the air atmosphere and is further enhanced for PiG.

scholarly journals Effects of Current on Arc Fabrication of Cu Nanoparticles

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
M. Z. Kassaee ◽  
F. Buazar ◽  
E. Motamedi
Keyword(s):  
Thermal Stability ◽  
Distilled Water ◽  
Face Centered Cubic ◽  
Cu Nanoparticles ◽  
Dta Analysis ◽  
Face Centered ◽  
Average Size ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Sem Analyses

Arc-fabricated copper nanoparticles (Cu Nps) size, morphology and the crystalline structure, as well as the yields of Nps appear sensitive to the applied currents (50–160 A) in distilled water. The results indicate that the sizes of Cu Nps are directly proportional to the currents employed. At 50 A, TEM, XRD, and SEM analyses show fabrication of relatively purest, the most dispersed, face-centered cubic (fcc) brown Cu Nps with rather smallest average size of 20 nm. At the same current, the TGA-DTA analysis reveals neither weight loss nor gain, indicating thermal stability of the fabricated Cu Nps.

scholarly journals Phosphated Avocado Seed: A Renewable Biomaterial for Preparing a Flame Retardant Biofiller

2021 ◽  
Author(s):  
DAVID Zuluaga-Parra ◽  
L.F Ramos-deValle ◽  
Saul Sanchez ◽  
J.R. Torres-Lubián ◽  
J.A. Rodríguez-Gonzalez ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Modification ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Morphological Changes ◽  
Ethylene Vinyl Acetate ◽  
Chemically Modified ◽  
Air Atmosphere ◽  
Thermal Stability Of ◽  
Avocado Seed

Abstract The cellulose and starch present in the avocado seed can be chemically modified to obtain biofillers with fire retarding characteristics. The resulting composites could be used as substitute of the corresponding halogenated composites. For this, the avocado seed was first washed, dehydrated and pulverized, and thereafter, chemically modified with phosphoric acid in the presence of urea. This was studied using infrared spectroscopy, nuclear magnetic resonance and X-Ray photoelectron spectroscopy, in order to determine the resulting chemical structure and confirm the presence of the proposed functional groups. In addition, scanning electron microscopy and elemental analysis were used, respectively, to establish the resulting morphological changes, as well as the elements present on the surface of the modified material. Thermogravimetric analysis was also carried out in order to establish the thermal stability of the material and predict the effect on the flame retardancy due to the mentioned chemical modification. Further tests established that the obtained modified structure and morphology of the avocado seed was highly dependent on the method used to dehydrate the pulverized avocado seed. It was also determined that chemical modification greatly increased the thermal stability of the avocado seed in air atmosphere. The flame-retardant effect of the modified avocado seed was assessed in polyethylene/ethylene-vinyl-acetate (PE/EVA) composites via cone calorimeter tests. These results showed that the modified avocado seed decreased the peak of the heat release rate (pHRR) by 50% and the total heat released (THR) by 15%. This phosphated avocado seed could be a good option as a renewable biofiller for polymer composites with enhanced flame-retardant properties.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

Sol-gel synthesis, solid sintering, and thermal stability of single-phase YCoO3

2012 ◽  
Vol 209 (7) ◽  
pp. 1219-1224 ◽  
Author(s):  
Guanlin Feng ◽  
Yanfeng Xue ◽  
Hongzhi Shen ◽  
Shuo Feng ◽  
Liang Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Single Phase ◽  
Sol Gel ◽  
Sol Gel Synthesis ◽  
Thermal Stability Of

Thermal Stability, Structure and Mechanical Properties of TiSiN Coatings Prepared by Reactive DC Magnetron Co-Sputtering

2006 ◽  
Vol 509 ◽  
pp. 93-98 ◽  
Author(s):  
L. García-González ◽  
J. Morales-Hernández ◽  
F.J. Espinoza-Beltrán ◽  
J. Muñoz-Saldaña ◽  
T. Scholz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Crystallite Size ◽  
Flow Rate ◽  
Air Atmosphere ◽  
Corning Glass ◽  
Stability Structure ◽  
Nitrogen Ratio ◽  
Steel Substrates ◽  
Thermal Stability Of

TiSiN coatings have been prepared by reactive DC magnetron co-sputtering on Corning glass and carbon steel substrates, using Ti-Si targets, with a constant Si:Ti area ratio of 0.2. The flow rate of nitrogen has been varied from 1.6 to 7.0 sccm, for a fixed argon flow rate of 25.0 sccm. We present a study of structure (texture, crystallite size and microstrain), chemical composition, and mechanical properties of the coatings and their dependence on the argon/nitrogen ratio. Moreover, a study of the thermal stability of the coatings has been performed by means of thermal annealing under oxidizing conditions (air atmosphere) at 500 and 600 °C. Coatings with the smallest crystallite size (∼2 nm) present the highest hardness (26 GPa) and the best thermal stability.

Thermal Behavior Prediction of MDPE Nanocomposite/Cloisite Na+ Using Artificial Neural Network and Neuro-Fuzzy Tools

2010 ◽  
Vol 1 (4) ◽  
Author(s):  
J. Sargolzaei ◽  
B. Ahangari
Keyword(s):  
Neural Network ◽  
Thermal Stability ◽  
Artificial Neural Network ◽  
Thermal Behavior ◽  
Fuzzy Inference ◽  
Air Atmosphere ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Inference Systems ◽  
Thermal Stability Of

Recently, we successfully prepared medium density polyethylene (MDPE) nanocomposite with 3 wt %, 6 wt %, and 9 wt % cloisite Na+ and the thermal stability of nanocomposite was investigated using the thermogravimetric analysis (TGA). The TGA in air atmosphere showed significantly improved thermal stability of 3 wt %, 6 wt %, and 9 wt % cloisite Na+ nanocomposite in comparison to pure MDPE. In this paper, the results of TGA of MDPE/cloisite Na+ nanocomposites were predicted by the artificial neural network (ANN). The ANN and adaptive neural fuzzy inference systems (ANFIS) models were developed to predict the degradation of MDPE/cloisite Na+ nanocomposite with temperature. The results revealed that there was a good agreement between predicted thermal behavior and actual values. The findings of this study also showed that the artificial neural networks and ANFIS techniques can be applied as a powerful tool.

Chemical and Thermal Stability of Multiple Ions Doped Non-Stoichiometric Nanoapatite Heat-Treated in CO2 and Air Atmospheres

2014 ◽  
Vol 925 ◽  
pp. 77-81
Author(s):  
K. Jamuna Thevi ◽  
Mohammed Rafiq Abdul Kadir ◽  
Hendra Hermawan
Keyword(s):  
Thermal Stability ◽  
Nanocrystalline Phase ◽  
Secondary Phases ◽  
Wet Precipitation ◽  
Carbonate Ions ◽  
Precipitation Technique ◽  
Heat Treated ◽  
Phase Pure ◽  
20 Nm ◽  
Thermal Stability Of

Nanostructured apatite has been widely used as a bone substitute material due to its close resemblance to human bone mineral. To further mimic biological apatites, multiple ions doped non-stoichiometric nanoapatite has been studied. A nanosized apatite (NAp-2) containing Mg (1.09 wt%), Na (0.15 wt%), K (0.008 wt%) and CO32- (5.18 wt%) was synthesized by a wet precipitation technique. The presence of these ions in NAp-2 was detected using ICP. Broad diffraction peaks of XRD results indicated the presence of nanocrystalline phase pure NAp-2. The primary particle size of the resulted powder was ~ 20 nm, typical of bone crystal size, estimated using Scherrers equation. Based on CHN results, the NAp-2 powders showed a total loss of 51 and 78% of carbonate ions when heat-treated at 900°C in both CO2 and air atmospheres, respectively. This indicates that the heat-treatment in CO2 flux has reduced the carbonate ions lost from the NAp-2. A highly crystalline HA phase was formed in the ionic doped NAp-2 without secondary phases, indicating a thermal stability of this powder at 900°C in CO2 and air atmospheres. Thus, this study demonstrated that a phase pure multiple ions doped nanoapatite was synthesized using a wet precipitation technique.

Investigation on the Thermal Stability of the Compounds Y3Fe29-xCrx

2013 ◽  
Vol 820 ◽  
pp. 71-74
Author(s):  
Xiao Hua Wang ◽  
Wei He ◽  
Ling Min Zeng
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Single Phase ◽  
Binary Compound ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Transition Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

Binary compound Y3Fe29cannot be directly formed by rare earth Y and Fe and the third element M (non-iron transition elements) must be introduced to form ternary compound Y3(Fe,M)29. In this work, six alloys with compositions of the Y3Fe29-xCrx(x=1,2,3,4,5,6) were prepared and investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and differential thermal analysis (DTA). The study on the thermal stability of these compounds points to that the compoundY3(Fe,Cr)29is a high temperature phase and exists above 1100K. The alloys with single-phase of Y3(Fe,Cr)29was decomposed into Y2(Fe,Cr)17and Y(Fe,Cr)12annealed at high temperature 1100K.

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