Low-Temperature Synthesis and Characterization of Single-Phase BiFeO3 Nano-Crystallites

2012 ◽  
Vol 164 ◽  
pp. 115-119
Author(s):  
Hui Fen Guo ◽  
Shu Xia Guo ◽  
Li Ben Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Crystallization Process ◽  
Exothermic Peak ◽  
Scanning Calorimetry ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
Intermediate Phases

Single-phase BiFeO3 (BFO) nano-crystallites were successfully synthesized in the temperature range of 500  750 oC by a simple diluted HNO3 sol method. During the crystallization process no intermediate phases were observed. As an example, we studied the electronic structure and thermodynamic stability of the BFO nano-crystallites calcined at 750 oC by X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC). The XPS showed that the oxidation state of Fe is Fe3+. The DSC indicated a novel exothermic peak at about 769 oC during cooling, which might be due to Bi2Fe4O9 or some other phases produced in the decomposition of BFO at high temperature.

scholarly journals Low-Temperature Synthesis of Solution Processable Carbon Nitride Polymers

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1646
Author(s):  
Junyi Li ◽  
Neeta Karjule ◽  
Jiani Qin ◽  
Ying Wang ◽  
Jesús Barrio ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Spatial Organization ◽  
Surface Display ◽  
Liquid Media ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
N2 Atmosphere ◽  
Carbon Nitride Materials

Carbon nitride materials require high temperatures (>500 °C) for their preparation, which entails substantial energy consumption. Furthermore, the high reaction temperature limits the materials’ processability and the control over their elemental composition. Therefore, alternative synthetic pathways that operate under milder conditions are still very much sought after. In this work, we prepared semiconductive carbon nitride (CN) polymers at low temperatures (300 °C) by carrying out the thermal condensation of triaminopyrimidine and acetoguanamine under a N2 atmosphere. These molecules are isomers: they display the same chemical formula but a different spatial distribution of their elements. X-ray photoelectron spectroscopy (XPS) experiments and electrochemical and photophysical characterization confirm that the initial spatial organization strongly determines the chemical composition and electronic structure of the materials, which, thanks to the preservation of functional groups in their surface, display excellent processability in liquid media.

scholarly journals Low temperature synthesis and characterization of Mn3O4 nanoparticles

2007 ◽  
Vol 5 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Abdülhadi Baykal ◽  
Yüksel Köseoğlu ◽  
Mehmet Şenel
Keyword(s):  
Particle Size ◽  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Synthesis And Characterization ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
Peak Broadening ◽  
Mn3o4 Nanoparticles

AbstractHeating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements confirm a typical Mn2+signal with a highly resolved hyperfine structure.

The Effect of Sample Substrate on the Structural Properties of Co-Deposited Films of A-Ge:H

1990 ◽  
Vol 192 ◽  
Author(s):  
S.J. Jones ◽  
W.A. Turner ◽  
D. Pang ◽  
W. Paul
Keyword(s):  
Yield Strength ◽  
Crystallization Process ◽  
Exothermic Peak ◽  
High Yield ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Strength Differential ◽  
Substrate Temperatures ◽  
Deposited Films

ABSTRACTResults from structural measurements on r.f. glow discharge produced a-Ge:H films have been found to be substrate dependent. The variations in the results were found to depend on both the substrate temperature, Ts, and the substrate yield strength. Differential scanning calorimetry results were particularly affected by these parameters. For films prepared at Ts = 150°C, the DSC spectra contain two exothermic peaks when the films are deposited on low yield strength substrates while only one exothermic peak is present for films deposited on high yield strength substrates. One exothermic DSC peak is seen in spectra for all films prepared at Ts = 300°C no matter what substrates were used. This DSC spectral dependence is attributed to differences in the microstructure of films deposited at the two substrate temperatures, as seen in TEM micrographs. X-ray diffraction measurements performed on films annealed to various temperatures show that all of the exothermic DSC peaks described above are associated with the crystallization process. Thus, for the films prepared at low Ts, crystallization is either a one or two step process depending on the yield strength of the substrate.

Sputter-deposition and characterization of paramelaconite

2003 ◽  
Vol 18 (7) ◽  
pp. 1535-1542 ◽  
Author(s):  
K. J. Blobaum ◽  
D. Van Heerden ◽  
A. J. Wagner ◽  
D. H. Fairbrother ◽  
T. P. Weihs
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metastable Phase ◽  
Heat Of Formation ◽  
Sputter Deposition ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multilayer Foils ◽  
Out Of Plane ◽  
Processing Techniques

While processing techniques for deposition of CuOx/Al multilayer foils were being developed, a method for synthesizing paramelaconite (Cu4O3) was serendipitously discovered. These paramelaconite films were successfully synthesized by sputter-deposition from a CuO target. Milligram quantities of uncontaminated material were produced enabling new studies of the morphology, stoichiometry, and thermodynamics of this unique copper oxide. At moderate temperatures, equiaxed paramelaconite grains deposited with a strong out-of-plane texture; at lower temperatures the paramelaconite grains showed no texture but were columnar in geometry. X-ray photoelectron spectroscopy showed that the as-deposited Cu4O3 had a nonstoichiometric Cu:O ratio of 1.7:1; the ratio of Cu+ to Cu2+ was 1.8:1. On heating, this phase decomposed into CuO and Cu2O at temperatures ranging from 400 to 530 °C. Using differential scanning calorimetry, the heat of formation and Gibbs free energy for Cu4O3 were estimated to be −453 and −279 kJ/mol, respectively. On the basis of these calculations and our observations, we confirmed that Cu4O3 is a metastable phase.

Synthesis and Characterization of a POSS-Urethane Hybrid Coating for Use in the Corrosion Protection of Metal

2005 ◽  
Vol 23 ◽  
pp. 231-234 ◽  
Author(s):  
Matthew Oaten ◽  
Namita Roy Choudhury
Keyword(s):  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Hybrid Coating ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Clean Steel ◽  
X Ray ◽  
Oligomeric Silsesquioxane ◽  
Steel Substrates

The potential of cyclic silsesquioxanes as flexible coatings has been explored in this work for corrosion protection of metal. A polyurethane coating containing an inorganic polyhedral oligomeric silsesquioxane (POSS) was synthesized and characterized by means of photo-acoustic infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle and modulated differential scanning calorimetry (MDSC). The coating has been applied to clean steel substrates via dip and spin coating. The POSS based hybrid coating is found to be uniform, dense and essentially defect free. XPS shows that the coating forms a lamellar layered structure on the substrate.

Thermal Characterization of the Interaction of Silanes with a Dihydroxy Vulcanized Fluoroelastomer

2006 ◽  
Vol 79 (5) ◽  
pp. 765-782
Author(s):  
Michael Benjamin Sands ◽  
Vijay Subramanian ◽  
Guangzhao Mao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Vinylidene Fluoride ◽  
Thermal Characterization ◽  
Peak Shift ◽  
Amine Group ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Lower Temperature ◽  
Bisphenol Af

Abstract The reactivity of aminosilane and vinylsilane with a dihydroxy (Bisphenol AF) crosslinkable fluoroelastomer containing only vinylidene fluoride (VF2) and hexafluoropropylene (HFP) was monitored using Differential Scanning Calorimetry (DSC) and X-ray Photoelectron Spectroscopy (XPS). The DSC results showed that the introduction of an aminosilane, or a combination of aminosilane and vinylsilane solutions, to the cure system of the fluoroelastomer resulted in a peak shift. This shift indicates that crosslinking in fluoroelastomer-silane system occurs at a lower temperature when aminosilane is present. Results also confirm that the organofunctional group on the silane reacts with the elastomer. XPS analysis of the silane-coated fluoroelastomer heated at 120 °C, 160 °C and 200 °C reveals that dehydrofluorination of the polymer is one of the steps in the reaction. It is our hypothesis that the amine group on the aminosilane is a contributor to the dehydrofluorination of the fluoroelastomer.

Chemical synthesis and characterization of polyaniline-molybdenum trisulfide composite

1999 ◽  
Vol 14 (5) ◽  
pp. 1805-1813 ◽  
Author(s):  
Florence Fusalba ◽  
Daniel Bélanger
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Synthesis And Characterization ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
X Ray ◽  
Scanning Electron

A novel polyaniline-molybdenum trisulfide composite has been prepared by chemical polymerization from an acidic (1 M HCl) aqueous solution containing aniline and ammonium tetrathiomolybdate. The presence of molybdenum trisulfide in the polyaniline matrix induces morphological change to the polymer as evidenced by scanning electron micrographs. X-ray diffraction and differential scanning calorimetry indicate that polyaniline-molybdenum trisulfide is slightly less crystalline than polyaniline-HCl. X-ray photoelectron spectroscopy (XPS) and elemental analysis have been used to confirm the presence of molybdenum trisulfide in the polymer matrix. The XPS data also confirm that molybdenum trisulfide and tetrathiomolybdate anions are present with polyaniline to form a new inorganic-organic composite.

scholarly journals Low temperature synthesis and characterization of single phase multi-component fluorite oxide nanoparticle sols

RSC Advances ◽  
2019 ◽  
Vol 9 (46) ◽  
pp. 26825-26830 ◽  
Author(s):  
Mariappan Anandkumar ◽  
Saswata Bhattacharya ◽  
Atul Suresh Deshpande
Keyword(s):  
Low Temperature ◽  
Acidic Medium ◽  
Single Phase ◽  
Synthesis And Characterization ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Oxide Nanoparticle ◽  
Co Precipitation

Fully crystalline single phase multi-component fluorite oxide (Gd0.2La0.2Y0.2Hf0.2Zr0.2O2 and Gd0.2La0.2Ce0.2Hf0.2Zr0.2O2) nanoparticle sols were synthesized at low temperature (≤80 °C) by co-precipitation followed by peptization in acidic medium.

Preparation and Characterization of APTES Modified Bioglass

2008 ◽  
Vol 368-372 ◽  
pp. 1215-1217
Author(s):  
Li Ren ◽  
Tian Yi Yang ◽  
Ying Gang Zhao ◽  
Na Ru Zhao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Structures ◽  
Polymer Materials ◽  
Attenuated Total Reflectance ◽  
Scanning Calorimetry ◽  
Total Reflectance ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Sbf Solution

Bioglass (BG) particles were treated by 3-aminopropyltriethoxysilane (APTES) in order to improve the interface compatibility with polymer materials. The surface structures of modified BG were characterized through Fourier transformed infrared spectroscopy with attenuated total reflectance accessory, thermogravimetric analysis, differential scanning calorimetry analysis and X-ray photoelectron spectroscopy. The results showed that APTES was successfully grafted on the surface of BG. The biomineralization properties of APTES modified bioglass were also studied through FTIR, XRD and SEM. Results showed that hydroxylcarbonateapatite (HCA) was formed on the surface of modified BG after soaked into SBF solution. It was shown that the APTES modified BG could possess good mineralization properties and could be intended as a composition of scaffolds for bone tissue engineering applications.

scholarly journals Investigation on the Effect of Hyperbranched Polyester Grafted Graphene Oxide on the Crystallization Behaviors of β-Nucleated Isotactic Polypropylene

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1988 ◽  
Author(s):  
Yansong Yu ◽  
Xi Jiang ◽  
Yiwei Fang ◽  
Jinyao Chen ◽  
Jian Kang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Isotactic Polypropylene ◽  
Photoelectron Spectroscopy ◽  
Crystallization Process ◽  
Hyperbranched Polyester ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystallization Behaviors ◽  
Transmission Electron

In this article, hyperbranched polyester grafted graphene oxide (GO) was successfully prepared. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were performed for its characterizations. On the other hand, differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were also performed to study its influences on non-isothermal crystallization behaviors of β-nucleated isotactic polypropylene (β-iPP). The grafting ratios of hyperbranched polyester with different supermolecular structures were calculated to be 19.8–24.0 wt %, which increase with the degree of branching. The results showed that the grafting of hyperbranched polyester was advantageous in increasing the crystallization peak temperature Tp and decreasing the crystallization activation energy ΔE of β-iPP/GO composites, which contributed to the iPP’s crystallization process. Moreover, under all cooling rates (2, 5, 10, 20, 40 °C/min), crystallinities of β-iPP/GO were greatly improved after being grafted with hyperbranched polyester, because of the increase of the relative contents of α-phase αc and the average α-crystal sizes.

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