Fabrication of Nanoporous Ceramic Thin Films: De-alloying and Self-organized Template Formation Onamorphous Substrates

2002 ◽  
Vol 17 (1) ◽  
pp. 115-126 ◽  
Author(s):  
Maggie Paulose ◽  
Oomman K. Varghese ◽  
Craig A. Grimes
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Sol Gel ◽  
Oxide Ceramic ◽  
Porous Network ◽  
Self Organized ◽  
Ceramic Thin Films ◽  
Transmission Electron ◽  
Amorphous Substrate ◽  
Drying Conditions

Sol-gel-derived metal oxide ceramic thin films deposited onto amorphous iron-rich substrates were found to form self-organized nanoporous structures dependent upon the extent to which the substrate is de-alloyed, a function of the substrate alloycomposition, acid concentration of the sol, and film drying conditions. Field emission scanning electron microscopy, transmission electron microscopy, and x-ray energy dispersive analysis were used to investigate details of the porous structure formation.Our studies showed the more electrochemically active elements in the amorphous substrate are de-alloyed by the sol in high-humidity environments, whereupon the liberated elements form oxides replicating the de-alloyed substrate matrix resulting in athree dimensional porous network structure.

Sol-gel processing of nanocrystalline haematite thin films

1997 ◽  
Vol 12 (6) ◽  
pp. 1441-1444 ◽  
Author(s):  
L. Armelao ◽  
A. Armigliato ◽  
R. Bozio ◽  
P. Colombo
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Single Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Processing

The microstructure of Fe2O3 sol-gel thin films, obtained from Fe(OCH2CH3)3, was investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. Samples were nanocrystalline from 400 °C to 1000 °C, and the crystallized phase was haematite. In the coatings, the α–Fe2O3 clusters were dispersed as single particles in a network of amorphous ferric oxide.

Growth and Characterizations of Relaxor-Based Pb(Mg1/3Nb2/3)O3-PbTiO3 Thin Films by Sol-Gel Method

2007 ◽  
Vol 280-283 ◽  
pp. 839-844
Author(s):  
Hui Qing Fan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Sol Gel ◽  
Silicon Substrates ◽  
Final Annealing ◽  
Gel Method ◽  
Sol Gel Method ◽  
Phase Development ◽  
Transmission Electron ◽  
Pt Films

Relaxor-based 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) thin films were grown epitaxially on silicon substrates by sol-gel method and PbO cover coat technique, and investigated by x-ray diffraction, auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The phase development and microstrure evolution of the PMN-PT film were significantly affected by the final annealing temperature and time. A perovskite PMN-PT film was obtained after annealing at 850oC for 1 min. Then, highly <100>-oriented and textured PMN-PT films could be achieved by using a LaNiO3 perovskite template.

Phase separation in SiO2–TiO2 gel and glassy films studied by atomic force microscopy and transmission electron microscopy

2001 ◽  
Vol 16 (6) ◽  
pp. 1626-1631 ◽  
Author(s):  
A. Karthikeyan ◽  
Rui M. Almeida
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Phase Separation ◽  
Sol Gel ◽  
Force Microscopy ◽  
Pure Silica ◽  
Atomic Force ◽  
Transmission Electron

An investigation of phase separation phenomena in gel and glassy thin films of silica–titania, with TiO2 contents of 20 and 40 mol%, has been carried out by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The thin films were prepared by spin coating of a precursor sol on silicon wafers. Both the TEM measurements (carried out on scrapped thin film flakes) and the AFM measurements (carried out on films coated on the silicon substrates) for samples with different heat treatments suggest that spinodal-like structural inhomogeneities occur in these samples, unlike the corresponding observations in pure silica films, which are known to be homogeneous. Changes in the microstructure of the films have been noticed with the thermal treatment, in agreement with earlier x-ray photoemission studies. The finer characteristic dimensions of the phase separated regions reveal that silica–titania samples prepared by sol-gel processing exhibit a more intimate mixing of the phases.

Microstructural evolution during pyrolysis of triol-based sol-gel single-layer Pb(Zr0.53Ti0.47)O3 thin films

2002 ◽  
Vol 17 (8) ◽  
pp. 2066-2074 ◽  
Author(s):  
Zhaoxia Zhou ◽  
Ian M. Reaney ◽  
David Hind ◽  
Steven J. Milne ◽  
Andy P. Brown ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Microstructural Evolution ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Single Layer ◽  
Face Centered Cubic ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

Advanced analytical transmission electron microscopy has been used to investigate microstructural evolution during pyrolysis in triol-based sol-gel thin films. At pyrolysis temperatures up to 300 °C, the films remained amorphous; however, nanometer-sized precipitates were observed in films heat-treated up to 400 °C for 10 min. Analytical transmission electron microscopy indicated that the precipitates were Pb-rich, as well as deficient in O, Ti, and Zr. Films pyrolyzed up to 500 °C for 10 min were composed of a nanocrystalline pyrochlore phase; however, pores could be observed, situated in the same position as the nanometer-sized precipitates at 400 °C. Face-centered cubic Pb-rich crystallites were also present on the surface of pyrolyzed films but absent in the fully crystallized films annealed at 650 °C. A tentative mechanism is proposed to explain these observations.

Transmission Electron Microscopy of Pzt Thin-Films Prepared by A Sol-Gel Technique

1993 ◽  
Vol 310 ◽  
Author(s):  
Supapan Seraphin ◽  
Dan Zhou ◽  
G. Teowee ◽  
J.M. Boulton ◽  
D.R. Uhlmann
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Chemical Compositions ◽  
Pzt Thin Films ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Gel Technique

AbstractThe microstructure of lead zirconate titanate (PZT) thin films prepared by a sol-gel technique was investigated using transmission electron microscopy (TEM) and transmission electron diffraction. We investigated the microstructure of three sets of thin films with different chemical compositions: PZT 53/47 films with no excess PbO; with excess PbO; and PZT 65/35 with no excess PbO. All samples were fired for 30 minutes at temperatures ranging from 400C to 700C. Incorporation of excess PbO in the 53/47 film fired at 450C resulted in polycrystalline perovskite grains with an average grain size of less than 0.1 μm. Grain boundaries are decorated by 5-10 nm diameter precipitates possibly caused by the segregation of remnant pyrochlore or excess PbO. The films have high values of dielectric constant (up to 2500) when fired at 700C. PZT 65/35 fired at 700C consists of two distinct phases: a fine-grained matrix of pyrochlore, and 10-μm diameter rosettes of perovskite. The correlations between the compositions, the microstructure of the films, and their processing conditions on the one hand, and ferroelectric properties on the other are discussed.

Identification of extended defect and interface related luminescence lines in polycrystalline ZnO thin films grown by sol–gel process

RSC Advances ◽  
2016 ◽  
Vol 6 (51) ◽  
pp. 44987-44992 ◽  
Author(s):  
Sophie Guillemin ◽  
Vincent Consonni ◽  
Laetitia Rapenne ◽  
Eirini Sarigiannidou ◽  
Fabrice Donatini ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Extended Defects ◽  
Extended Defect ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Cathodoluminescence Imaging

The luminescence lines related to extended defects and interfaces in polycrystalline ZnO thin films grown by sol–gel process are investigated by combining photoluminescence and cathodoluminescence imaging with high-resolution transmission electron microscopy.

Photocatalysis Property of Titania-Based Thin Films with Covalent Grafting PANi as Sensitizer

2012 ◽  
Vol 549 ◽  
pp. 470-473 ◽  
Author(s):  
Hong Quan Liu ◽  
Fang Lian ◽  
Lin Zhang ◽  
Meng Liu
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Tetrabutyl Titanate ◽  
Porous Films ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Covalent Grafting ◽  
Titania Sol

Polyaniline sensitized titania thin film were fabricated by spin-coating from Ti-precursor containing PEG as surfactant via a sol-gel technique, in which titania-sol was synthesized by hydrolysis of tetrabutyl titanate in water-alcohol solution. The films were characterized by X-ray diffraction, high resolution transmission electron microscopy, field-emission scanning electron microscopy, thermal gravity-differential scanning calorimetry, and tested under self-made photocatalysis instrument. The results showed the synthesized porous films provided the active surfaces for self-polymerization of aniline. Compared with bare TiO2 thin films, the composite films displayed a enhanced photocatalytic activity and could be the potential photocatalyst for indoor air decontamination or self-cleaning films.

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

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