Information & explanations, latest texts & monographs on
Amorphous_solid (including recent related patents.)
Amorphous solidAn amorphous solid is a solid in which there is no long-range order of the positions of the atoms. (Solids in which there is long-range atomic order are called crystalline solids.) Most classes of solid materials can be found or prepared in an amorphous form. For instance, common window glass is a ceramic, most polymers are amorphous, and even some amorphous metallic alloys can be prepared under special processing conditions (such as rapid solidification and ion implantation). There are many ways in which amorphous solids can be made. If a liquid is cooled rapidly enough to avoid crystallization, an amorphous solid called a glass is formed below the glass transition temperature. Amorphous solids produced by other routes, such as ion implantation are, technically speaking, not glasses. In common parlance, the term glass refers to amorphous oxides, and especially silicates (compounds based on silicon and oxygen). To avoid confusion, other types of glass often are referred to with a modifier, such as the term 'metallic glass' to refer to amorphous metallic alloys. It is difficult to make a distinction between truly amorphous solids and crystalline solids in which the size of the crystals is very small (less than two nanometers). Even amorphous materials have some short-range order among the atomic positions (over length scales of about one nanometer). Furthermore, in very small crystals a large fraction of the atoms are located at or near the surface of the crystal; relaxation of the surface and interfacial effects distort the atomic positions, decreasing the structural order. Even the most advanced structural characterization techniques, such as x-ray diffraction and transmission electron microscopy, have difficulty in distinguishing between amorphous and crystalline structures on these length scales. The transition from the liquid state to the glass, at a temperature below the equilibrium melting point of the material, is called the glass transition. From a practical point of view, the glass transition temperature is defined empirically as the temperature at which the viscosity of the liquid exceeds a certain value (commonly 1013 Pascal-seconds). The transition temperature depends on cooling rate, with the glass transition occurring at higher temperatures for faster cooling rates. The precise nature of the glass transition is the subject of ongoing research. While it is clear that the glass transition is not a first-order thermodynamic transiton (such as melting), there is debate as to whether it is a higher-order transition, or merely a kinetic effect. Some examples of amorphous solids are butter, glass, and rubber.This article is adapted from from Wikipedia All Wikipedia article text is available under the terms of the GNU Free Documentation License The Physics of Amorphous Solids by Richard Zallen Physics of Amorphous Metals by Nikolai P. Kovalenko Electronic Processes in Non-Crystalline Materials (International Series of Monographs on Physics) by Nevill Mott Structure and Bonding in Noncrystalline Solids by George E. Walrafen Current Topics on Non-Crystalline Solids: Proceedings by International Workshop on Non-Crystalline Solids 1986 San Feliu De Gu Amorphous and Microcrystalline Semiconductor Devices, Volume II: Materials and Device Physics by Jerzy Kanicki New Kinds of Phase Transitions: Transformation in Disordered Substances (NATO Science by NATO Advanced Research Workshop on New Kinds of Phase Transitions: Tra Photo-Induced Metastability in Amorphous Semiconductors by Alexander V. Kolobov Disordered Materials by Paolo M. Ossi Tunneling Systems in Amorphous and Crystalline Solids by Pablo Esquinazi The Glass Transition by Ernst-Joachim Donth Specialist Meting on Amorphous Carbon by S. R. P. Silva Amorphous Solids and the Liquid State (Physics of Solids and Liquids) by Norman March Hydrogen in Disordered and Amorphous Solids (NATO Asi Series B, Physics, Vol 136) by Gust Bambakidis The Magnetism of Amorphous Metals and Alloys by J.A. Fernandez-Baca Recent Amorphous_solid related patents From USPTO: 6716990: Process and intermediates for the preparation of imidazopyridines 6716978: Therapeutically active compounds based on indazole bioisostere replacement of catechol in PDE4 inhibitors 6716961: Chiral peptide nucleic acids with a N-aminoethyl-d-proline backbone 6716862: 5-(Substituted)-5-(substitutedsulfonyl or sulfanyl) thiazolidine-2,4-diones useful for inhibition of farnesyl-protein transferase 6716849: Substituted phenylcyclohexane carboxylic acid amides that have an adenosine uptake inhibiting effect 6716833: Acetylenic .alpha.-amino acid-based sulfonamide hydroxamic acid tace inhibitors 6716808: Detergent compositions comprising hybrid zeolite builders containing an occluded nonsilicate 6713645: Substituted tricyclics 6713602: Synthetic procedures for peptide nucleic acids 6713481: Crystalline antifungal polymorph 6713471: Substituted heterocycle fused gamma-carbolines 6713464: Derivatives of 3,3-diphenylpropylamines 6713178: Highly tetrahedral amorphous carbon coating on glass 6710296: Method and apparatus for free-forging of metal structures 6710168: Glycopeptide antibiotics, combinatorial libraries of glycopeptide antibiotics and methods of producing same 6710071: Difluoromethylene aromatic ethers as inhibitors of glycine transport 6710063: Activators of PPAR delta 6710058: Monocyclic or bicyclic carbocycles and heterocycles as factor Xa inhibitors 6710055: Disubstituted bicyclic heterocycles, the preparation thereof, and their use as pharmaceutical compositions 6710007: Polymerization of olefinic compounds 6709806: Method of forming composite member 6706283: Controlled release by extrusion of solid amorphous dispersions of drugs 6706214: Composition and process for inhibiting corrosion of metallic substrates 6705771: Method of fusion splicing silica fiber with low-temperature multi-component glass fiber 6703407: Benzofuran compounds, compositions, and methods 6699975: Fluorescent quenching detection reagents and methods 6699891: Npyy5 antagonists 6699855: Inhibitors of hepatitis C virus NS3 protease 6696614: Catalyst for steam cracking reactions and related preparation process 6696573: Processes for the preparation of tricyclic amino alcohol derivatives 6696555: 3'-Desoxypentopyranosyl nucleic acid, its production and its use 6696496: Low water-soluble venlafaxine salts 6696494: .alpha.-hydroxyarylbutanamine inhibitors of aspartyl protease 6696476: Pyranoindazoles and their use for the treatment of glaucoma 6696467: Quinoline derivatives 6696461: Tricyclic imidazopyridines 6696458: Compositions and formulations of 9-nitrocamptothecin polymorphs and methods of use thereof 6696457: Morphinoid compounds 6696438: Cyclic amino acid compounds, pharmaceutical compositions comprising same, and methods for inhibiting .beta.-amyloid peptide release and/or its synthesis by use of such compounds 6696002: Co-continuous interconnecting channel morphology polymer having modified surface properties 6693199: Method of making HIV protease inhibitors 6693188: N-acetyl-D-glucosamine and process for producing N-acetyl-D-glucosamine 6693123: Inhibitors of protein isoprenyl transferases 6693120: Spray drying of thrombin inhibitors 6693109: Spiro compounds as inhibitors of fibrinogen-dependent platelet aggregation 6692695: Industrial scale barrier technology for preservation of sensitive biological materials 6692590: Alloy with metallic glass and quasi-crystalline properties 6689794: Aromatic sulfone hydroxamates and their use as protease inhibitors 6689790: Substituted triazolopyridine compounds |