In Situ Fluorescence Probing of Molecular Mobility and Chemical Changes during Formation of Dip-Coated Sol−Gel Silica Thin Films

2000 ◽  
Vol 12 (1) ◽  
pp. 231-235 ◽  
Author(s):  
Michael H. Huang ◽  
Hermes M. Soyez ◽  
Bruce S. Dunn ◽  
Jeffrey I. Zink
Keyword(s):  
Thin Films ◽  
Molecular Mobility ◽  
Sol Gel ◽  
Chemical Changes ◽  
Silica Thin Films ◽  
Fluorescence Probing

In Situ Fluorescence Probing of the Chemical Changes during Sol-Gel Thin Film Formation

1995 ◽  
Vol 78 (6) ◽  
pp. 1640-1648 ◽  
Author(s):  
Fumito Nishida ◽  
John M. McKiernan ◽  
Bruce Dunn ◽  
Jeffrey I. Zink ◽  
C. Jeffrey Brinker ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Formation ◽  
Sol Gel ◽  
Chemical Changes ◽  
Fluorescence Probing ◽  
Thin Film Formation

Chemical Analyses of Sol/Gel Surfaces and Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
Carlo G. Pantano ◽  
C. A. Houser ◽  
R. K. Brow
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Films ◽  
Alumina Films ◽  
Surface Analysis Techniques ◽  
Relative Water ◽  
Temperature Programmed

ABSTRACTThe application of surface analysis techniques to the characterization of sol/gel surfaces and thin films is described. Secondary-ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS) and sputter-induced photon spectroscopy (SIPS) are used to measure the composition of multicomponent silicate films, the relative water content of alumina films, the nitrogen content of ammonia treated silica films, and the depth profiles for films on black chrome. The determination of chemical structure using XPS and SIMS is also discussed. Finally, a brief introduction to temperature-programmed desorption (TPD) and its potential for studying surface chemical reactions, in situ, is presented.

Humidity Effects on Porous Silica Thin Films

1995 ◽  
Vol 411 ◽  
Author(s):  
J. R. Kokan ◽  
R. A. Gerhardt
Keyword(s):  
Thin Films ◽  
Ac Conductivity ◽  
Sol Gel ◽  
Porous Silica ◽  
Controlled Environment ◽  
Alkali Ions ◽  
Humidity Effects ◽  
Silica Thin Films ◽  
Environment Chamber ◽  
Humidity Sensitivity

ABSTRACTImpedance Spectroscopy is being used to study the humidity sensitivity of porous silica thin films. The films are processed via a colloidal sol-gel method which leaves some remnant potassium and sodium. Previous work on bulk porous silica samples processed by the same method showed that the dielectric properties and ac conductivity were very sensitive to changes in humidity. The aim of this work was to determine if the same dependencies could be found in the thin films. The capacitance, dielectric loss, and ac conductivity of the films were measured in a controlled environment chamber from 20–80% RH for frequencies ranging from 10Hz–10MHz. In addition to characterizing films with varying amounts of residual alkali ions obtained through leaching, we have also measured films that were surface doped with controlled amounts of KCl, LiCl, or NaCl. Relative humidity dependencies in the films are not as dramatic as in the bulk samples. The reasons for this behavior are not yet clear, but may be associated with the porosity, thickness, and surface area of the films.

Formation and characterization of high-density silver nanoparticles embedded in silica thin films by “in situ” self-reduction

2001 ◽  
Vol 16 (10) ◽  
pp. 2934-2938 ◽  
Author(s):  
G. Compagnini ◽  
M. M. Fragal´ ◽  
L. D'Urso ◽  
C. Spinella ◽  
O. Puglisi
Keyword(s):  
Thin Films ◽  
Silver Nanoparticles ◽  
High Density ◽  
Silver Particles ◽  
X Ray Diffraction ◽  
Optical Extinction ◽  
Organometallic Precursor ◽  
Silica Thin Films ◽  
20 Nm

Silver nanoparticles (10–20 nm) embedded into silica thin films have been obtained through the use of a silver organometallic precursor compound dissolved in Spin-On-Glass and subsequently spinned onto suitable substrates. In this paper we present a study of the shape, size, and distribution of silver particles through the use of microscopes, x-ray diffraction, and optical extinction. It has been observed that the obtained films are stable for annealing up to 500 °C with a progressive degradation above this temperature. Furthermore it is possible to obtain high-density silver particles up to 15% in weight without affecting the cluster size and shape.

Comparison of Several CU(I) and CU(II) Precursors for the Sol-Gel Preparation of High TC Superconducting Metal Oxides

1988 ◽  
Vol 121 ◽  
Author(s):  
Mariquita A. Accibal ◽  
Jonathan W. Draxton ◽  
Allen H. Gabor ◽  
Wayne L. Gladfelter ◽  
Beth Anne Hassler ◽  
...  
Keyword(s):  
Thin Films ◽  
Metal Oxides ◽  
Coordination Compounds ◽  
Sol Gel ◽  
High Tc ◽  
Superconducting Metal ◽  
Zero Resistance ◽  
Gel Preparation ◽  
Sol Gel Synthesis

ABSTRACTA comparison of the use of three different coordination compounds of copper as precursors for the sol-gel synthesis of YBa2Cu3O7-δ has been made. For yttrium, the tris(isopropoxide) was used exclusively, while the use of both Ba(O-i-Pr)2 and Ba(OCH2CH2OEt)2 (prepared in situ from Ba metal) as sources for Ba were studied. After dissolving Y(O-i-pr)3, a Ba source, and the copper(I) alkoxide, [Cu(O-i-Bu)]4, hydrolysis led immediately to an orange gelatinous solid which yielded YBa2Cu3O7-δ upon firing in oxygen. Copper(II) acetate was found to give heterogeneous mixtures under our conditions and was not further studied. Copper(II) acac (acac = acetylacetonate) yielded the best results. Partially hydrolyzed solutions of Cu(acac)2, Ba(OCH2CH2OEt)2, and Y(O-i-pr)3 were spin coated on SrTi03 (100) and fired under oxygen to give oriented (b axis normal to the surface) thin films of YBa2Cu3O7-δ. The onset of superconductivity for the films was 92 K, but they did not reach zero resistance until much lower temperatures.

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