SOL-GEL TECHNOLOGY FOR THIN FILMS, FIBERS, PREFORMS, ELECTRONICS, AND SPECIALTY SHAPES potx

SOL-GEL TECHNOLOGY FOR THIN FILMS, FIBERS, PREFORMS, ELECTRONICS, AND SPECIALTY SHAPES Edited by Lisa C Klein Center for Ceramics Research College of Engineering Rutgers-The State University of New Jersey Piscataway, New Jersey I PI n NOYES PUBLICATIONS Park Ridge, New Jersey, U.S.A Copyright @ 1998 by Noyes Publications No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without permission in writing from the Publisher Library of Congress Catalog Card Number: ISBN: 08155-1154-X Printed in the United States Published in the United States of America Noyes Publications Mill Road, Park Ridge, New Jersey 07656 87-34780 by 10987654 Library of Congress Cataloging-in-Publication Data Sol-Gel technology for thin films, fibers, preforms, electronics, and speciality shapes Bibliography: p Includes index Ceramic materials Glass fibers Thin films Colloids I Klein, Lisa C TP662.S65 1988 666.15 87-34780 ISBN 0-8155-1154-X To my daughter, Martha Ann Kinseiia, who was born while the book was in progress and To Dennis Ravaine, my scientific collaborator and friend, who passed away suddenly in 1986 MATERIALS SCIENCE AND PROCESS TECHNOLOGY SERIES Editors Rointan F Bunshah, University of California, Los Angeles (Materials Science and Technology) Gary E McGuire, Microelectronics Center of North Carolina (Electronic Materials and Processing) DEPOSITION TECHNOLOGIES FOR FILMS AND ments and Applications: by Rointan F Bunshah et al CHEMICAL Technology, COATINGS; VAPOR DEPOSITION FOR MICROELECTRONICS; and Applications: by Arthur Sherman Develop- Principles, SEMICONDUCTOR MATERIALS AND PROCESS TECHNOLOGY HANDBOOK; For Very Large Scale Integration (VLSI) and Ultra Large Scale Integration (ULSI): edited by Gary E McGuire SOL-GEL TRONICS, TECHNOLOGY AND SPECIALTY HYBRID MICROCIRCUIT esses, Design, Testing and Enlow FOR THIN SHAPES: FILMS, FIBERS, PREFORMS, edited by Lisa C Klein TECHNOLOGY by Production: HANDBOOK OF THIN FILM NIQUES; Principles, Methods, Klaus K Schuegraf HANDBOOK; James J Licari DEPOSITION Equipment ELEC- Materials, Procand Leonard R PROCESSES AND TECHand Applications: edited by Related Titles ADHESIVES TECHNOLOGY HANDBOOK OF THERMOSET HANDBOOK: PLASTICS: HANDBOOK OF CONTAMINATION Principles, Applications and Technology: by Arthur H Landrock edited by Sidney H Goodman CONTROL IN MICROELECTRONICS; edited by Donald L To/liver Contributors Philippe Carol S Ashley Sandia National Albuquerque, Colomban Groupe Laboratories de Chimie Laboratoire New Mexico Matiere du Solide de Physique de la Condensee John B Blum Ecole Polytechnique Norton Palaiseau, Company Northboro, Helmut de Chimie Laboratoire Matiere Dislich Schott du Solide de Physique Glaswerke Mainz, Jean Pierre Boilot Groupe France Massachusetts Federal Raymond Palaiseau, KMS Fusion, France L Downs Ann Arbor, Albuquerque, Matthias Laboratories A Ebner KMS Fusion, New Mexico Ann Arbor, Inc Michigan K Brow Department of Materials Jochen Science The Pennsylvania University Universitat State University Wurzburg, Park, Pennsylvania of Materials Park, H Garofalini Department Rutgers-The State State University New Jersey University Piscataway, Pennsylvania ix der West Germany Ceramics Science and Engineering The Pennsylvania lnstitut Am Habland Stephen Lee A Carman Department Fricke Physikalisches and Engineering University Inc Michigan Brinker Sandia National Richard of Condensee Ecole Polytechnique C Jeffrey Republic Germany de la New Jersey of x Contributors Lisa C Klein Ceramics Department Rutgers-The State University of New Jersey Piscataway, New Jersey William C LaCourse Alfred University Alfred New York Wayne J Miller KMS Fusion, Inc Ann Arbor, Michigan Shyama P Mukherjee IBM Corporation Endicott, New York George F Neilson Microgravity Science and Applications Group Jet Propulsion Laboratory California Institute of Technology Pasadena, California Richard B Pettit Sandia National Laboratories Albuquerque, New Mexico Carlo G Pantano Department of Materials Science and Engineering The Pennsylvania State University University Park, Pennsylvania Eliezer M Rabinovich AT&T Bell Laboratories Murray Hill, New Jersey Scott T Reed Sandia National Laboratories Albuquerque, New Mexico Sumio Sakka Institute for Chemical Research Kyoto University Uji, Kyoto-Fu, Japan Harold G Sowman 3M St Paul, Minnesota Ian M Thomas Lawrence Livermore National Laboratory University of California Livermore, California Michael C Weinberg Microgravity Science and Applications Group Jet Propulsion Laboratory California Institute of Technology Pasadena, California Masayuki Yamane Department of Inorganic Materials Tokyo Institute of Technology Tokyo, Japan NOTICE To the best of the Publisher’s knowledge the information contained in this publication is accurate; however, the Publisher assumes no liability for errors or any consequences arising from the use of the information contained herein Final determination of the suitability of any information, procedure, or product for use contemplated by any user, and the manner of that use, is the sole responsibility of the user Mention of trade names or commercial products does not consititute endorsement or recommendation for use by the Publisher The book is intended for informational purposes only The reader is warned that caution must always be exercised when dealing with hazardous materials, and expert advice should be obtained at all times when implementation is being considered xii Preface This book covers the principles, developments, techniques, and applications of sol-gel processing The solgel process is not new, however, a few commercial successes in the recent past have revived interest The commercial successes are largely in the area of thin films These films have been developed for optical, mechanical and electrical applications About one-third of this book covers thin films The second area where there has been commercial success is fibers These fibers whether spun or drawn may be continuous or woven The applications realized and projected are refractories, composite reinforcement and thermal insulation About one-third of this book covers fibers The third area encompasses the special applications such as preforms, microballoons and electronics Discussion of the chemistry, polymerization, drying and characterization are all necessary parts of a treatment of sol-gel processing The anticipated product of this effort is a book that covers the background and fundamentals Also, it evaluates the present technology and projects new directions short range and long range The graduate students at Rutgers University, P Anderson, H delambilly, T Gallo, T Lombardi and J Ryan, are thanked for their editorial assistance Visiting scientists Jean-Yves Chane-Ching and Henry Wautier served as reviewers Center for Ceramics Research Rutgers-The State University of New Jersey Piscataway, New Jersey December 1987 vii Lisa C Klein Contents I PART CHEMISTRY MULTICOMPONENT AND PHASE GLASSES TRANSFORMATIONS FROM THE SOL-GEL PROCESS .2 Ian M Thomas Historical .2 Introduction Preparation General .3 Al koxide-Salt Method Other Methods All-Alkoxide Properties Method Comparison Homogeneity with Conventional Glass 10 Purity Fabrication and Use 11 General .1 Bulk Glass by Melting Conclusions References .I1 Bulk Glass Without Commercial Melting Products SIMULATION OF THE SOL-GEL Stephen H Garofalini PROCESS Procedure Results and Discussion Conclusions References Introduction Computational XIII 12 I2 I3 I3 I6 I6 I8 23 26 26 xiv Contents PHASE TRANSFORMATION IN GELS: A COMPARISON OF THE PHASE TRANSFORMATION BEHAVIOR OF GEL-DERIVED AND ORDINARY Na*O-SiOz GLASSES Michael C Weinberg and George F Neilson Introduction Metastable Liquid-Liquid Immiscibility in NazO-SiOz Glass Immiscibility Temperatures Initial Study of Phase Separation of Gel-Derived Glass Morphology of Phase Separation Immiscibility Temperature Compositional Effects Factors Affecting Phase Separation Behavior Trace Impurities Water Structure Phase Separation Kinetics Recent Studies Crystallization of Na*O-SiOz Gel and Glass Summary and Conclusions References COATINGS, THIN PART II FILMS AND SURFACE 28 28 30 30 32 32 32 37 38 38 41 41 43 44 46 46 TREATMENT THIN FILMS FROM THE SOL-GEL PROCESS Helmut Dislich Introduction and Highlights of the Sol-Gel Process Principles of the Sol-Gel Dip Process Process Technology Process Advantages Other Coating Techniques Chemistry and Physical Principles of the Sol-Gel Dip Process General Comments Single Oxides Mixed Oxides Cermets .5 Non-Oxide Layers Multi-Component Oxide Layers Organic-Inorganic Layers Coated Products Based on Sol-Gel Technology Rear View Mirrors for Automobiles Solar Reflecting Glass (IROX) Anti-Reflective Coatings Other Surface Coated Glasses Sol-Gel Layers Under Development Antireflective Coatings Contrast Enhancing Filters for Data Display Screens Porous Antireflective Coatings in the UV-Range 50 50 51 52 52 54 54 54 55 57 58 58 60 63 63 64 67 68 68 69 69 69 Filters and Membranes by the Sol-Gel Process 393 ricate silica sheets so that their porosity and microstructure could be evaluated for a potential separation medium Experimental Techniques All solutions were prepared with distilled TEOS, distilled deionized water and reagent grade ethanol The solution compositions are listed in the table below, mol TEOS: x mols water, where x is 1.5, 2.5 or 16: 0.5 mol ethanol The ethanol and TEOS are mixed in a closed flask at room temperature Nitric acid is added to the required water from a molar solution The acidified water is then added to the stirring solution As hydrolysis begins, the solution becomes cloudy and the exothermic reaction heats the flask Shortly after, the solution clears Pressure built up in the flask is reduced by venting the flask The flask is cool after about hours Some of the ethanol is extracted by a so-called vacuum distillation This permits an increase in the density of the solution without substantial change in the molecular structure After cooling the reaction flask to about 5”C, a rush condenser leading to a cold trap and oil breather is attached The condenser is cooled with circulating acetone-dry ice The condenser is connected to a mechanical pump and a vacuum of about 10 mm Hg is drawn The temperature of the flask is raised until the solution starts to boil, somewhere betweenlO% and 20% After ethanol removal, the solutions are stored in airtight plastic bottles They not lose fluidity for several months Surface tension values for water, ethanol, TEOS and the three mixtures were measured using a Wilhelmy plate technique where a platinum plate is lifted from the surface of the liquid Because of the large surface area exposed during measurements with a Wilhelmy plate, this technique could not be used with gelling solutions The values reported in the table below are for solutions before vacuum distillation From this survey, the mixture with the lowest value was used for all further sample preparation Sheets of gel were formed by pouring the solution onto a bath of s-tetrabromoethane (acetylene tetrabromide CHBr2CHBr2) It was chosen for low reactivity, high density (2.96 g/ml) and high surface tension 54dynes/cm at 25°C As the solution is poured, it spreads evenly over the bath The solution has a density of about g/ml, so it remains on the surface A large area of solution becomes exposed to atmospheric moisture First, a skin forms on the solution, and then moisture penetrates through this layer so that the sheet can gel As soon as the layer has gelled, the sheet is peeled off of the bath or lifted with a wire ring The sheet is very flexible at this point but dries quickly to a fragile sample resembling wax paper To avoid curling, the sheets are suspended vertically in air to allow drying from both sides Dried sheets are typically 0.1 mm thick Dried sheets were examined with reflected light microscopy and scanning electron microscopy Results In order for a solution to spread into a sheet, the solution must have a surface tension less than that of the substrate, and the interfacial tension between solution and substrate should be low The measured surface tensions for the TEOS-water-ethanol solutions are listed in the following table The values are all lower than that for tetrabromoethane Nevertheless, the 2.5 and 16 mols 394 Sol-Gel Technology water solutions tended to ball up Only when the solution was in the partially hydrolyzed state with 1.5 mols water per mol TEOS was even spreading achieved Measured Surface Solution Tension Using Wilhelmy Plate Technique Surface Tension, dynes/cm (10-3 Newtons/mI at 20°C Ethanol TEOS 25.3 25.4 1.5 mols water/1 mol TEOS 25.8 2.5 mols water/1 mol TEOS 26.7 16 mols water/1 mol TEOS 31.9 Water 62.1 The optical micrographs, Figures and 5, show the top surface of the gel sheets This is the surface exposed to air Figure shows the surface in a wet condi tion and Figure shows the surface after some drying During hydrolysis, ethanol is produced It escapes to the top surface of the solution where the bubbles intersect the rapidly gelling skin (Figure 4) The bubbles leave a hemispherical depression As the gel becomes rigid, the hemispherical pores are pulled into an equilibrium arrangement which approaches close packing (Figure 5) Figure shows the bottom surface of the gel sheet which became rigid in contact with the tetrabromoethane Because gas was not free to escape through the bottom, there are a few pinholes, but no regular pattern of bubbles intersecting the surface Tetrabromoethane has no solubility for water or ethanol Figure 4: Top bles of various mol TEOS surface of wet sample sizes intersect free immediately surface Solution after removal contains from bath 1.5 mols water Bubper Filters Figure 5: Top size are drawn Figure 6: of sample approximately after into by the Sol-Gel gel has been air dried close packed Process Bubbles arrangement 395 of uniform Same solution as Figure surface and Membranes Bottom surface of sample cate escape of gas at solution-bath after interface gel has been air dried Same solution as Figure Pinholes indi The large pores of the top surface are connected to the pinholes of the bottom surface by circuitous channels and the microporosity The fine pores in the silica honeycomb between the large pores are shown in the scanning electron 396 SoJ-Gel Technology micrograph in Figure the intersection bubble shows that Figure 7: porosity Figure Bubbles Figure smaller bubbles Scanning electron fills silica between 8: Scanning rising to the shows is a diameter electron surface a typical were trapped before micrograph of top bubbles fracture and the depression Same solution they surface got to the exposed surface of air dried as Figure micrograph of are trapped in the bulk fracture It shows that is a hemisphere surface It also surface gel Micro- of Same solution air dried as Figure gel Filters and Membranes by the Sol-Gel Process 397 Discussion There are similarities ures through inversion membranes.30 the porosity solvent The organic The sequence solvent, gelation, In organic membranes of evaporation though portant it appears In acidified generally to mechanism solutions The moisture, allow there the through The tension is an mols which reaction polymer of water were droplets of of the solvent solution is more im- in the solution are polymers hydrolysis is no tendency formed as expected factor for the ab- within before are only drying, are ethoxy of the polymer determining the ease of permeation tension solutions of moisture are largely unhydrolyzed groups rather than hydroxy is low like that of ethanol hydrolyzed tended but for thin, glassy silicate met in the low water by the to ball the layer and a low value for the interfacial chains TEOS through for the solutions sheets are pliable is controlled intentionally per mol into gels is not entirely initial further important groups, and the surface tension solutions process is loss power in the silicate and fragile, These conditions hydrolysis along the and deple- and loss of residual separation the layer, in its intial stage the linear polymers groups complete have enough crosslinking A low value for the solution for spreading Because for the silicate eventually the sheets are brittle surface depletion of the During to give cohesive sheets The newly spreading capillary the mechanism be linear.24 of atmospheric drying are solvent cast materials, of the gel before the chemistry in Figas phase during the process up Yet the linear polymers after known of steps in the phase inversion The low water assumed sorption membranes shown membranes gel phase is the decreased that than its handling microstructure of organic contraction, phase in a continuous as a result clear, the membrane is a result of the immobilization tion of the solvent of volatile solvent between and the microstructure to a high degree with to ball up, indicating The up to 16 the conditions for spreading on an organic bath are not met The The surface tension gradually gel skin begins as a flexible During this maturing size of the bubbles of bubbles of the layer, the vapor escaping, while The resulting ing of hemispherical mind applications of replacing changes with lowest depressions energy to the atmosphere thickens to a rigid sheet pressure of ethanol the surface tension configuration It is this uniform of these materials organic filters exposure layer and eventually controls approximates configuration as filters and membranes in high temperature establishes the the arrangement close packthat brings to and the likelihood applications SUMMARY Sol-gel processing branes In this Chapter, few of them examples fit with but it is only microporous the requirements of filters and mem- have been given of ceramic involve sol-gel processing in some detail, exploit is a natural The technique in a very early stage Further and macroporous materials membranes and a used at Rutgers isdescribed work by the solgel is warranted process to 398 Sol-Gel Technology Acknowledgement The financial dustry-NSF tion, support Cooperative a grant from Alcoa Figures through were supplied tributed greatly Technology has supported Gallagher to this Chapter Claudia for Ceramics at Rutgers were supplied by Dennis Corporation this manuscript of the Center Program the work by Tom Kuchinow and her help in coordinating a University-ln- is appreciated In addi- on high surface area aluminas Lombardi The hard work Technical Research, University and Figures through of these colleagues has con- assistance was provided is thanked by Omicron for her preparation of this publication REFERENCES Lonsdale, H.K.,J Membrane Sci 10,81-181 (1982) Pusch, W and Walch, A., Angew Chem lnt Ed 21, 660-685 (1982) Dullien, F.A.C., Porous Media - Fluid Transport and Pore Structure, Academic Press, New York (1979) Lloyd, D.R (ed.), Materials Science of Synthetic Membranes, Am Chem Sot., Washington, D.C (1985) Elmer, T.H.,J Am Ceram Sot 57, 1051-1054 (1978) Tanaka, H., et al., J Non-Crystal Solids 65, 301-309 (1984) McMillan, P.W and Maddison, R., U.S Patent 4,473,476, Sept 25, 1984 Yamamoto, M., Sakata, J and Doi, H., U.S Patent 4,521,236, June 4,1985 Kingery, W.D., Bowen, H.K and Uhlmann, D.R., Introduction to Ceramics, 2nd Ed., Chapter 10, Wiley-Interscience, New York (1976) 10 Day, M.A and Reid, A., U.S Patent 4,526,885, July 2,1985 11 Kaiser, A and Schmidt, H., J Non-Crystal Solids63, 261-271 (1984) 12 Sakka, S., Kamiya, K., Makita, K and Yamamoto, Y., J Non-Crystal Solids 63, 223-235 (1984) 13 Kaiser, A., Schmidt, H and Bottner, H., J Membrane Science22, 257-268 (1985) 14 Philipp, G and Schmidt, H., J Non-Crystal Solids 63, 283-292 (1984) 15 Leenaars, A.F.M., Keizer, K and Burggraaf, A.J., Studies in Inorganic Chemistry, Vol 3, 401-404, (R Metselaar, H.J.M Heijligers and J Schoonman, eds.), Elsevier, Amsterdam (1983) 16 Leenaars, A.F.M., Keizer, K and Burggraaf, A.J., J Mater Sci 10, 10771088 (1984) 17 Teichner, S.J., Nicholson, G.A., Vicarini, M.A and Gardes, G.E.E., Adv in Colloid Interface Sci 5, 245-273 18 Rubin, M and Lampert, C.M., Solar Energy Materials 7, 393-400 (1983) 19 Caps, R and Fricke, J., lnt J War Energy 3, 13 (1984) 20 Dumas, J., et al.,J Mat Sci Lett 4, 1089-1091 (1985) 21 Lecloux, A.J., in Catalysis-Science and Technology, Vol 2, 172-230, (J.R Anderson and M Boudart, eds.), Springer, Berlin (1981) 22 Klein, L.C and Garvey, G.J., in Better Ceramics Through Chemistry, 33-39, (C.J Brinker, D.R Ulrich and D.E Clark, eds.), Elsevier, New York (1984) Filters 23 Lombardi, T., Rutgers 24 Brinker, 25 Klein, of High surface University, and Membranes area October, sol-gel New New York (1986), 26 Sakka, Dislich, H and Hinz, 28 Klein, (A Gallo, alumina, Masters 399 thesis, Clearfield (1984) in sol-gel processed and D.L Cocke, silicates, eds.), in Design Plenum Press, to appear S and Kamiya, 27 L.C., Solids 63, 45-49 of microstructures Materials, derived Process 1986 C.J., et al., J Non-Crystal L.C., Design by the Sol-Gel K., J Non-Crystal P., J Non-Crystal T.A and Garvey, Solids48,31-46 Solids48, l-16 G.J., J Non-Crystal (1982) (1982) Solids 63, 23-33 (1984) 29 Gallagher, 30 Kesting, (1971) D and Klein, R.E., Synthetic L.C., J Colloid Polymer Interface Membranes, Sci 109, 40-45 116, McGraw-Hill, (1986) New York Index Acetates 163 double -4, acetonates Acetyl -7, partial -8 titania- 194 purification zirconia -195 synthesis 298 Acoustic levitation Activation -255 for viscous Advanced fibers -303 flow batteries storage Aerogel -12, tiles -304, -278 thin 314 Alumina-boria-silica 205 transparent monolithic -226, 241 -226 262 202, Aluminum Ammonia 344 Anion silicates -304, -28, 347 in silica -281 -267 289 coatings double -253, index porous 290, layer -67, graded -44 338 Alkoxides 83, 94 82 -89 single layer -83 Antistatic -3 -80 -69 quarterwave CaO -338 definition substitutions Antireflective -378 borosilicates with nitrate -6 treatment of silica films hydroxyl-281 nitrogen -111, 152, 377 -311 sodium 162, 173 fluorine -342 Alkali -162 -87 chlorine diffusion Alkali -141, films of sols -189 Alkali -162 fibers 111 Aging of gels -98, rubidium fibers Alumina-silica fibers -70, -87 Alumina-boria granular lithium -385 films for energy -226 Alcogel -156 filters transl ucent AerosilTM 338 Alumina energy for conduction -4, 250 -197, Aspect 400 coatings ratio -72 of shells -335 - Index Atomic absorption - 38, analysis - 72 conductive - 54,98 multilayer - 53 - 142,205,227,343, Autoclaving for tubes 353,386 passivation - 272 Barium nitrate - Barium titanate - 60, 301 BET method - 208,274,386 Bloating - 205, 217,280 Blowing Complex - 110 Comminution Ball milling bicarbonates Colloidal silica - 9,90, LUDOXTM- - 350 - 353, 368 163,264,334 - 249, alkoxide 342 - 4,298 Composite piezoelectric syntactic - 162, 164,272 Boric acid - 8, 333 Borosilicates - 181,290 Boria with alumina 184, 249, 260 - 333 Computer - 299 foam - 331 - 17 simulations Condensation polymerization - 4, 185 and baria - 95 Conductivity - 2, 11,249 Bulk glass - 75 scuff agents carbonates urea - 306 electrochromic 342 401 - 73 electrical ionic - 127, 303,314 - 262 Cab-0-SilTM Cadmium proton - 60,73 stannate - 320 - 301 Calcination Capacitors melting gravity - 174 fibers for hydrolysis Conventional - 202, Coulter 203,211,388 acid - 303,305 - 231 Containerless Carbon-containing Catalyst thermal melting - 5, 142, 397 - 144,227 - 255 - IO, 249 - 273 - 187, 214, 392 counter Crosslinking Crystallization ammonia in micro- conditions - 29, 168, 289, 299,311 base - 185, 274 Catalyst supports Cerenkov - 159, 180 Defects - 226 detectors bubbles - 219,248,272,282 Cermet radiation-induced fibers - 180 titania-precious Chemical - 57 metal Dehydration leaching - 179,290, chlorine resistance layer Chemical vapor deposition - 73 (CVD) 87, 110,125,248,290 - 256 - 256 class 10000 Coagulation Coatings of colloids - 385 (see also Layers, thin films) adhesion antistatic - 55 - 72 of treatments - 222, 253, 280 - - 222 - 204,214 relative - 214, 233 skeletal - 213 theoretical - 213,290 Deprotonation - 25 by basic medium - 201 Deuterium-tritium (DT) - 330 thermal Density Clean room conditions class 100 - 253 chemical 384 Chemical - 248 - 248 structural Dielectric breakdown strength - 110, 127, 130 402 Sol-Gel Dielectric Technology as-drawn- (continued) blown insulators128, 301 Differential thermal analysis - directional fabric layers -70 Dilatometry Drying roving freezing silica- -176 142 -174 strength- 154, 164, 173, 191 titania -155 with discrete -287 metal forces -184, woven 202, controlled humidity critical point drying control -179 tive zirconia -268 drying Fiber -205 chemical -156 reinforced ceramics Field 288 Films -268, hypercritical evacuation and gate oxides thick -205, -165, 202 (see Thin Filtration- -382 osmosis 353 films) 179, 256 dialysis 253 -383 reverse osmosis Electrochromic coatings Flame -306 Electrochromism -306 Electron microscopy replication barriers Flocculation Fourier ceramic device reaction Ellipsometry -89, -382 -177 -286 transform specular 32 Electrophilic -110 -75 thin 227,253 natural evaporation -342, -175 tubes -179 addi- -204 (DCCA) freeze drying Etching - yarn -175 266 Electronic particles 180 -204 capillary vacuum -154 -176 strand -26 -267 cation 162, -179 noncontinuous -4, 248 Doping anion 174 -150, mat-176 -215 Dip coating -51,84 Dispersion -266 II II double processing Distillation -153, filament 174, 184 74 masks -110 Diffusor -184 carbon-containing continuous 168,211,350 Diffusion barrier layers -72, Diffusion 146, 191 fiber infrared reflectance Fresnel coefficients -104 Fumed -296 -203 silica -142, 201, ( FT I R ) -98 232, 262, 283 123 85, 98 Extinction coefficient -231, 237 Gas chromatography -211,344 Gel classifications- Fabrication bulk films Fiber definition glass -11 -51, Fiberizing- Gelation 84 drawing -140, 184, 190 of temperature reversible Germanium 141 alumina-boria -185, -185, oxide -204, 261 261 -288, 341 Glass -163 alumina-boria-silica 186, 260 -260 irreversible 188 Fibers alumina- effect 150, -260 -164 noneauilibrium state -28 266 Index Glass-ceramic oxides boria - 162, - 338 Infrared phosphorous 216,267 - 288 oxide nhomogeneities - 288 silica fibers absorption Infrared 164,272,288 - 288,341 germania - 177, 180 - 37,209,234 spectroscopy - 34, 122, Infiltrated - 59, 307 Glass forming norganic oxide - 338 - 288, 322 potassium oxide - 288 sodium oxide - 288 salts Glass modifying ntercalation lead oxide nterference Glass transition - 334 - 363 I nterlayer dielectrics - 301 Ion exchange - 347 bulls eye image 28,217,252 - 28 - 273 definition Green body I ROXTM- Lanthanum - 219 High temperature -6 nitrate - 330 Laser power fuel cells (such propagation - chemical resistance (HGS) - dielectric - 110, 301 diffusion barrier glass microspheres 330 - 227, 333 - 3, 16, 187, 200 by atmospheric oxidation - 5, moisture -5 -4 infrared sensor - 299 - 143, polycondensation thin film - 299 Lead zirconate - 158 - 37, 187,209,247 Homogeneity - 2,9,200 Hot pressing - 201 Hydroxyls - 298 Lead zirconate 187,249 titanate lead (lanthanum) titanate temperature - 43 Lithium - 127,247 intrinsic - 247 trace - 38, 247 Macroporosity transition Magnetic tin oxide confinement - 298 - 74, phase separation - 30 - 306 approximations 85,125 metals - 39, 247 lndium (PLZT) insertion Lorentz-Lorenz in glass extrinsic Inertial (PZT) zirconate 318 Liquid-liquid Impurities - 305 - 298 pyroelectric partial Immiscibility barrier semiconductor Lead titanate 55, 144,309,344,397 Hydrolytic - 60 - 74, 131 organic-inorganic spray drying Hydrolysis - 72, 74 diffusor - 155 Hydrogel - 73 - 70 nonoxide - 58,74 - 180,267 acid thin films) 304 Hydrofluoric - 247 Layers (see also Coatings, zirconia) as calcia stabilized 330 - 239 Laser fusion - 85, 343 step heating - 221 Hydrosol number - 88, 185 - 217 rapid slow point for silica Knudsen rate isothermal Hollow 53,64 Isoelectric Heating constant - 306 - 57, 83 compounds filters nterferometry - temperature - 5, 309 -6 (ITO) - 60 fusion (ICF) - 241 - 74, 181,296, materials 301 - Mass spectrometry - 346 - 403 404 Sol-Gel Technology Mercury porosimetry - 272,386 Metal alkoxides - 3, 141, 200,250 Metal halides - 209, 248 Metal organic derived (MOD) - 34, 331,366 Metal salts - 6, 141 Metastable immiscibility in sodium silicates - 29 Microelectronics seals - 110,300 Microporosity - 179,217 Microradiography - 334 Microstructure of fibers - 165 of films - 91 of filters - 389 of solid electrolytes - 318 MIS devices - 127 Molecular dynamics - 16 Molecular orbital calculations - 16 Monoliths crack-free - 200, 252,272 silica - 150, 279 Mullite - 164, 175 NASICON (sodium superionic conductor) - 304 NASIGEL/LISIGEL (sodium/ lithium superionic gel) - 306 NASIGLASILISIGLAS (sodium/ lithium superionic glass) - 306 NEXTELTM- 176 Nitrates - 6, 311 Nitridation in ammonia - 111 Nitrogen sorption - 206, 386 NMR spectroscopy - 309 Nucleation - 247 Nucleophilic reaction - 203 Optical attenuation - 234,247, 291 Optical fiber preform - 142,276, 290 Optical microscopy - 335, 394 Organic-inorganic hybrids films - 60 for filters - 385 with epoxy - 177 with Kevlar - 177 with polyimide - 177 Organic salts - ORMOSILS (organically modified silicates) - 314 Owens-Illinois, Inc - Oxidation barrier layer - 74, 131 Oxidation of chlorine - 222 of organics - 171 Oxygens bridging - 17 non-bridging - 18 Passivation coating - 110 Piezoelectric - 298 transducer - 298 pH of silica solutions high (pH = 9-l I) - 90,185,203, 274 low (pH