Thermochemical Processes Episode 14

384 Index Superexchange, in magnetic oxides, 237, 238 Supported catalysts, 128–9, 133–4, 138 Surface diffusion, 15 in catalysts, 128 in sintering, 204–7, 303 Surface energy, of alloys, 126, 139–40 of ionic solids, 232–3 of metals, 12–15, 125–6, 196–7, 295–6 of nuclei, 25, 27 Surface enrichment of alloys, 126, 139–40 Surface morphology of catalysts, 122–5 of metals, and temperature on, 199 due to grain boundaries, 195–6, 197 of nuclei, 27–8 and surface energy, 125–6 techniques for studying, 120–2 and vaporization, 12–15 Swalin equation for diffusion of liquid metals, 291–4 Synthesis gas, production of, 134–5 syntheses from, 142 Tantalum, 93, 349 Tantalum silicides, vaporization of, 97–9 Temperature, choice of for CVD, 107 Debye, 165–6 effect of, on diffusion, 30, 171–3, 174 on gas-phase reactions, 45–6 on gas transport properties, 112 on nucleation of metallic glasses, 297–300 Ternary gaseous systems, 95–7, 97–9 Terrace surfaces, 122, 123–4 Thermal conductivity, 164, 166–8 of gases, 110, 115 of metal oxides, 167–8 of metals, 167–8, 296–7 Thermal decomposition, to produce thin films, 106–8 Thermal deposition, see Chemical vapour deposition (CVD); Vapour deposition Thermal diffusion, 102, 103 Thermal spikes, in metal sputtering, 18–19 Thermal transport, in condensed phases, 163–4 in gas–solid reactions, 277–9 in the vapour phase, 89–91, 102–3 Thin films, formation of, 24–37 by gas-phase dissociation, 43 by laser techniques, 16–17, 21, 82–3 by metal sputtering, 17–20 from nuclei, 28–30 by vapour deposition, 3–16, 106–8 interdiffusion and interaction in, 219–21 orientation effects on, 126 thickness of, 107–8 Third-order reactions, 50, 51 Thorium oxide (thoria), 12, 159, 239–2 Time dependence of reactions, 52–3 T–T–N curves for nucleation of metallic glasses, 297–8, 300 T–T–T diagrams for iron-carbon system, 187–8 Titanium, oxidation of, 254 Titanium carbide, composite of, with chromium, 268 diffusion in, 183–4 preparation of thin films of, 10, 107, 219 Titanium–carbon system, oxidation of, 267–8 Titanium diboride, CVD of, 106, 107 composite of, with MgO, 216–17 Titanium halides, 68 Titanium oxides, 254, 226, 313 Titanium silicide, , 219 Titanium–silicon system, 268 Index 385 Transition metals, carburizing of, 262–4 as industrial catalysts, 129–143 passim interstitial atoms in, 182 Transition state theory, 42, 47–9, 183 Translational energy of molecules, 43 Transport number, 160 Trimolecular reactions, 50, 51 Tungsten, 186, 266, 271–2 Tungsten carbide, sintering of, 301 Tungsten–nickel system, sintering of, 303–4 Tungsten oxides, structure of, 226 Turbulent flow, 58–9, 277–9 Unimolecular reactions, 50–2 Uranium, 194–5, 346 Uranium dioxide, diffusion in, 228–9, 249–50 grain growth of, 101–2, 250 redistribution of fission products in, 249–50 thermal conductivity of, 167 Uranium tetrahalides, reduction of, 346 Vacant sites, 31–2, 33 energy of formation of, 173–4 in metal oxides, 225 migration of, 173–5, 176, 181, 208–9 Vacuum refining of liquid steel, 361–3 van Arkel refining of metals, 91–2 van der Waals equation for real gases, 112–14 Vanadates, hot corrosion by, 319–20, 321 Vanadium, 174, 186 Vaporization, evaporation coefficients, 11–16 rate of, 7, 8–10 thermodynamics of, 4 Vapour deposition, from organometallic compounds, 68–71 for thin film preparation, 3–16, 42–3, 62–3 Vapour pressure, effect of thermal diffusion on, 103 of the elements, 4, 38–41 of two-component systems, 8 Vapour-phase transport, 86–116 grain growth by, 100–2, 250 of uranium dioxide in nuclear fuel rods, 250 Vibrational energy of molecules, 44 Viscosity, of gases, 110, 115 of liquid metals, 294–5 of liquid silicates, 309 of molten metal halides, 317 of slags, 323–4, 335 Volume diffusion, 170–6, 181, 198–9 in Ostwald ripening, 211, 212 in oxidation, 251–2, 255 in sintering of metals, 204–7 passim Vycor glass, 311 Wagner equations for growth kinetics, 211, 212 Water-cooled nuclear reactors, 194 Water-gas shift reaction, 129–30, 131–2 Work-hardening of metals, 181 Wulff’s theorem, 15 Yttrium, effect of, on nickel oxidation, 255 in ceramic superconductors 217 Yttrium iron garnet, 238–9 Zero point energy, 44 Zeroth-order reactions, 118–19 Zinc, extraction of, 330–1, 332, 334–5 refinement and separation of, 357–60 vaporization of, 21 Zinc oxide, fuming of, 332 nanoparticles of, 21 point defects in, 225, 226–8 Zinc sulphide, preparation of thin films of, 16 Zircalloy, 194 386 Index Zirconium, extraction of, 345–6, 349 oxidation of, 265–6 in PZT materials, 159–60, 236 refining and purification of, 92–3 vapour-phase transport of, 87–8, 89–91 Zirconium diboride, CVD of, 107 Zirconium dioxide (zirconia), electron transport in, 159 formation of, 265–6 in fuel cells, 244 in oxygen sensors, pumps and membranes, 239–43, 247 vacancy formation in, 228 vaporization of, 12, 16 Zirconium tetrachloride, reduction of, 345–6 Zirconium titanate, 159–60 Zone refining, 304–6 ... - tailieumienphi.vn