Microstructural Characterization of Sol-Gel Derived Lead Titanate Deposited On Silica

1993 ◽  
Vol 310 ◽  
Author(s):  
Joseph M. Schwartz ◽  
Lorraine Falter Francis ◽  
Lanny D. Schmidt
Keyword(s):  
Lead Titanate ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Microstructural Characterization ◽  
Barrier Materials ◽  
Support Materials ◽  
Treatment Conditions ◽  
Transmission Electron ◽  
Platinum Particles

AbstractThe microstructural evolution of lead titanate prepared by a sol-gel method was examined using transmission electron microscopy (TEM) following treatments in air at progressively higher temperatures. TEM specimens were prepared by spin coating a film or dispersing particles onto specimen grids coated with SiO2 or SiO2 with a barrier layer. The effects of different barrier materials, thermal treatment conditions, and the addition of platinum particles were examined. Lead titanate formed crystalline perovskite at ∼550-600°C on all support materials examined. On SiO2 supports, the pyrochlore phase formed at lower temperatures and converted partially to perovskite at higher temperatures. Barrier layers of TiO2, A12O3 and polyimide prevented pyrochlore formation.

Preparation and Characterization of Metal Alkoxide Derived Epitaxial Lead Titanate Based Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Keiichi Nashimoto ◽  
Shigetoshi Nakamura
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Solid Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Guided Wave ◽  
Metal Alkoxide ◽  
Rocking Curve ◽  
Sol Gel Process

ABSTRACTEpitaxial and highly oriented lead titanate based thin films were prepared by a sol-gel process using non-hydrolyzed methoxyethoxide precursors and RTA process. PbTiO3 crystallized with preferred (001) or (100) orientation on SrTiO3 (100) and MgO (100). Solid phase (001) oriented epitaxial growth of PZT on SrTio3 was observed at 425°C, directly from the amorphous phase. That of PZT on MgO was observed at temperatures above 550°C, after the formation of pyrochlore phase. The PZT on SrTiO3 had a single (001) orientation and rocking curve full width at half maximum less than 0.08°. PZT showed a weak preferred (111) orientation on sapphire (0001) substrates, while highly (111) oriented PLT thin films were obtained on them. The guided wave modes were excited by a prism coupling for PZT thin films crystallized on SrTiO3 and MgO. Electrical properties of epitaxial PZT and PLT thin films on Nb-SrTiO3 substrates were characterized.

The Microstructural Characterization of Nanocrystalline CeO2 Ceramics Produced by the Sol-Gel Method

1994 ◽  
Vol 343 ◽  
Author(s):  
F. Czerwinski ◽  
J.A. Szpunar
Keyword(s):  
Sol Gel ◽  
Microstructural Characterization ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Structure Of Coatings ◽  
Heating Up

ABSTRACTCeO2 ceramics were manufactured in the form of surface coatings deposited onto various substrates by sol-gel technology. The size of the CeO2 crystallites, dried at room temperature, was about 5 nm and did not change significantly after heating, up to 680 K. Further increase of the temperature resulted in a rapid growth of crystallites. The process of growth depends also on the film thickness and nature of substrate. The results obtained using thermogravimetric analysis (TGA) and infrared spectroscopy (IR) demonstrated that the thermal decomposition of gel was completed at about 750 K. There was no evident texture in both the as-deposited state and after heat-treatment. X-ray diffraction (XRD), the atomic force microscopy (AFM), and transmission electron microscopy (TEM) were used to characterize the structure of coatings. The examples of application of CeO2 ceramics as coatings for high temperature corrosion protection are presented. The role of size of CeO2 particles in modification of grain boundary transport is discussed.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Characterization of ordered mesoporous films on silicon (001) surface using X-ray and electron diffraction

2005 ◽  
Vol 38 (1) ◽  
pp. 211-216 ◽  
Author(s):  
Pang-Hung Liu ◽  
Kuei-Jung Chao ◽  
Xing-Jian Guo ◽  
Kuo-Ying Huang ◽  
Yen-Ru Lee ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Film ◽  
Continuous Film ◽  
X Ray ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Direction Dependence

A continuous silica film with well aligned mesochannels parallel to the Si(001) surface was found to be formed through sol–gel dip-coating of a silica precursor with nonionic ethylene oxide surfactant. Two two-dimensional mesoporous structures in centered and non-centered rectangular symmetries and with the short axes of elongated ellipsoidal pores normal to the surface were observed by X-ray and electron diffraction. Detailed transmission electron microscopy investigations were employed to view the direction dependence of the channel or pore packing in the continuous film.

Microstructural characterization of sol–gel derived Pb1−xLaxTiO3 ferroelectrics

2005 ◽  
Vol 388 (2) ◽  
pp. 308-313 ◽  
Author(s):  
Jun Chen ◽  
Xianran Xing ◽  
Ranbo Yu ◽  
Jinxia Deng ◽  
Guirong Liu
Keyword(s):  
Sol Gel ◽  
Microstructural Characterization

Preparation and Characterization of Pt/Superfine Mesocarbon Microbead Powers Electrocatalysts

2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin
Keyword(s):  
Reduction Method ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Platinum Particles ◽  
Platinum Electrocatalyst ◽  
Direct Methanol

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).

CONTROLLED SYNTHESIS AND CHARACTERIZATION OF TiO2 NANOPARTICLES VIA A SOL–GEL METHOD

2004 ◽  
Vol 03 (06) ◽  
pp. 749-755 ◽  
Author(s):  
YING LI ◽  
SUO HON LIM ◽  
TIM WHITE
Keyword(s):  
Sol Gel ◽  
Critical Role ◽  
Rietveld Analysis ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
Gelation Temperature ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron

The properties influencing the photocatalytic activity of TiO 2 particles have been suggested to include the surface area, crystallinity, crystallite size and crystal structure. Therefore, manipulation of the microstructure of titania, especially of nanocrystalline powders, is very important in the preparative process. In this study, nanocrystalline TiO 2 powders with controlled particle size and phase composition were synthesized at low temperature (<80°C) by a modified sol–gel method. The effects of gelation temperature were systematically investigated. It was found that this parameter played a critical role in determining the crystallinity of single phase anatase. With increasing gelation temperature, the crystallinity of anatase improved initially and then decreased if the temperature was raised to 80°C. These nanomaterials were characterized comprehensively by powder X-ray diffraction (including Rietveld analysis), high-resolution transmission electron microscopy, DSC/TGA thermal analysis and UV–Vis spectrometry.

scholarly journals Chemical and Microstructural Characterization of pH and [Ca2+] Dependent Sol-Gel Transitions in Mucin Biopolymer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Austin Curnutt ◽  
Kaylee Smith ◽  
Emily Darrow ◽  
Keisha B. Walters
Keyword(s):  
Sol Gel ◽  
Microstructural Characterization

Microstructural Characterization of Ni-Al Alloyed Layer under Laser Rapid Solidification Condition

2011 ◽  
Vol 328-330 ◽  
pp. 565-568
Author(s):  
Yue Yang ◽  
Hua Wu
Keyword(s):  
Cross Section ◽  
Pulsed Laser ◽  
Microstructural Characterization ◽  
Eutectic Growth ◽  
Nickel Layer ◽  
Solidification Condition ◽  
Melted Zone ◽  
Transmission Electron ◽  
Pulsed Laser Irradiation

Nickel layer electroless deposited on aluminum substrate was alloyed by Nd-YAG pulsed laser irradiation. Solidification microstructure was characterized through cross section, showing typical microstructure that were located in upper and middle melted zone and interface of melted pool and substrate, respectively. The microstructure was analyzed by transmission electron microscopy (TEM). Followed by the observations, the eutectic growth process was analyzed.

Microstructural Characterization of Pt/Ti and RuO2 Electrodes on SiO2/Si Annealed in the Oxygen Ambient

1996 ◽  
Vol 433 ◽  
Author(s):  
Jeong Soo Lee ◽  
Hyun JA Kwon ◽  
Young Woo Jeong ◽  
Hyun HA Kim ◽  
Kyu HO Park ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Film Surface ◽  
Microstructural Characterization ◽  
Silicide Phase ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Degree Of Oxidation ◽  
Thin Interlayer ◽  
Increasing Temperature

AbstractMicrostructures and interdiffusions of Pt/Ti/SiO2/Si and RuO2/SiO2/Si during annealing in O2 were investigated using x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The degree of oxidation and the interdiffusion of elements have remarkably increased with increasing temperature above 500 °C for the Pt/Ti/SiO2/Si case. The generation of Pt hillocks commenced at 500 °C. The Pt-silicide phase was also observed near the TiOx/SiO2 interface. The microstructural variations occurred to only a small amount for the RuO2/SiO2/Si case over the temperature range 300 – 700 °C. While there was no hillock formation, the RuO2 film surface was roughened by the thermal grooving phenomenon. A thin interlayer phase was found at the RuO2/SiO2 interface.

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