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	Amorphous solid
		An amorphous solid is a solid in which the atoms do not have an ordered atomic structure.
		Solids which are not amorphous are called crystalline solids.
		Amorphous solids which are not oxides can also be called glass, but are often referred to with special terminology, for example amorphous metals could be called 'metallic glasses'.
	www.ebroadcast.com.au /lookup/encyclopedia/am/Amorphous.html (277 words)

	Online Encyclopedia and Dictionary - Amorphous solid
		Amorphous solids produced by other routes, such as ion implantation and thin-film deposition are, technically speaking, not glasses.
		This technique is known as ion implantation, and only forms amorphous solids if the material is too cold for atoms to diffuse back to their original positions as the process continues.
		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 nanometres).
	fact-archive.com /encyclopedia/Amorphous_solid (929 words)

	Amorphous solid Summary
		A crystalline solid may be transformed into an amorphous solid by alpha-particle radiation emitted by uranium or thorium atoms contained in the crystal itself.
		For instance, common window glass is an amorphous ceramic, many polymers (such as polystyrene) are amorphous, and even foods such as cotton candy are amorphous solids.
		Amorphous materials are often prepared by rapidly cooling molten material.
	www.bookrags.com /Amorphous_solid (1920 words)

	Solid State Structure
		A solid substance with its atoms held apart at equilibrium spacing, but with no long-range periodicity in atom location in its structure is an amorphous solid.
		Amorphous solids do not show a sharp phase change from solid to liquid at a definite melting point, but rather soften gradually when they are heated.
		Crystal structures may be conveniently specified by describing the arrangement within the solid of a small representative group of atoms or molecules, called the ‘unit cell.’ By multiplying identical unit cells in three directions, the location of all the particles in the crystal is determined.
	www.ndt-ed.org /EducationResources/CommunityCollege/Materials/Structure/solidstate.htm (800 words)

	Is glass liquid or solid?
		As the solid is heated the molecules vibrate about their position in the lattice until, at the melting point, the crystal breaks down and the molecules start to flow.
		Solids, liquids and gases are ideal behaviours characterised by properties such as compressibility, viscosity, elasticity, strength and hardness.
		There is no clear answer to the question "Is glass solid or liquid?." In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid or simply that glass is another state of matter which is neither liquid or solid.
	www.weburbia.demon.co.uk /physics/glass.html (2566 words)

	Erythrosin B Phosphorescence Monitors Molecular Mobility and Dynamic Site Heterogeneity in Amorphous Sucrose ... (Site not responding. Last check: 2007-10-14)
		Amorphous solids form during physical processes such as rapid cooling of melts or drying of solutions that frustrate formation of a regular crystalline lattice (Zallen, 1983).
		Amorphous solids are thermally plastic, being hard, rigid, and brittle at low temperature, and soft, flexible, and pliable at high temperature.
		Mobility within the amorphous solid is typically discussed in terms of the mechanical or dielectric loss peaks detected as a function of temperature or frequency in amorphous polymers (McCrum et al., 1967).
	www.findarticles.com /p/articles/mi_qa3938/is_200505/ai_n13636309 (625 words)

	Physics News Graphics: Amorphous Solid Water (Site not responding. Last check: 2007-10-14)
		Amorphous solid water is a non-crystalline form of water that can be made in the lab at very cold temperatures (a).
		Above a temperature of 140 K, the disorderly frozen molecules begin to form tiny crystalline grains of ice (b).
		) molecules, trapped under the amorphous water layer, can now escape by percolating up between the ice grains and emerge as a "molecular volcano" (c).
	www.aip.org /png/html/asw.htm (74 words)

	States of Matter: Solids (Site not responding. Last check: 2007-10-14)
		Amorphous solids are formed when the viscosity of a liquid increases to a point that prevents flow.
		In any case when amorphous solids are heated the conversion to a liquid is a gradual softening rather than a sharp phase change.
		That is because the solid and liquid are in equilibrium at the freezing point until either all the solid melts or all the liquid freezes.
	home.att.net /~v.d.singleton/genchem/solid.htm (4655 words)

	Glass: Liquid or Solid -- Science vs. an Urban Legend
		A material is amorphous when it has no long-range order, that is, when there is no regularity in the arrangement of its molecular constituents on a scale larger than a few times the size of these groups.
		An amorphous (or synonymously, non-crystalline) material can be defined as one which is topologically disordered and which does not exhibit either the long-range translational order (periodicity) characteristic of single crystals, or the long-range orientational order characteristic of quasicrystals.
		(Thus, by definition, all glasses are amorphous, but not all amorphous solids are necessarily glassy.) The glass transition is marked (as a function of temperature) either by a change in slope of extensive thermodynamic quantities (e.g., volume or entropy) or, equivalently, as a discontinuity in derivative quantities (e.g., specific heat or thermal expansivity).
	dwb.unl.edu /teacher/nsf/c01/c01links/www.ualberta.ca/~bderksen/florin.html (2007 words)

	Devitrification of Amorphous Celecoxib
		Amorphous CEL was prepared in situ in the analytical instruments, as well as in laboratory, by quench-cooling of melt process, and analyzed by dynamic mechanical thermal analysis, differential scanning calorimetry, microscopy, and Fourier-transform infrared spectroscopy.
		Amorphous CEL prepared in situ in the analytical instruments was resistant to crystallization under the influence of temperature and/or pressure, because of its protection from the external environment during preparation.
		Amorphous CEL in the laboratory was prepared by melting the crystalline drug in a stainless steel beaker over a hot plate (approximately 175°C) and quench cooling over crushed ice.
	www.aapspharmscitech.org /view.asp?art=pt060232 (3462 words)

	Amorphous: World of Earth Science
		Amorphous solids are made of the same elements that produce crystalline solids, often mixed in the same ratios.
		Although few amorphous solids beside glasses occur naturally, an amorphous form of virtually any substance can be manufactured by sufficiently rapid quenching of the liquid phase or by depositing atoms from the vapor phase directly onto a cool substrate.
		Most natural amorphous solids are formed by fast quenching, but not all.
	science.enotes.com /earth-science/amorphous (355 words)

	Polymer Morphology
		Amorphous materials, by contrast, have their molecules arranged randomly and in long chains which twist and curve around one-another, making large regions of highly structured morphology unlikely.
		That is, they form mixtures of small crystals and amorphous material and melt over a range of temperature instead of at a single melting point.
		solid is formed when the chains have little orientation throughout the bulk polymer.
	plc.cwru.edu /tutorial/enhanced/files/polymers/orient/orient.htm (825 words)

	amorphous solid -- Encyclopædia Britannica
		Solids and liquids are both forms of condensed matter; both are composed of atoms in close proximity to each other.
		It is now known that the amorphous solid state is almost a universal property of condensable matter.
		It is important to understand that, although differences do exist between the properties of amorphous and crystalline solids, it is nevertheless broadly true that amorphous solids exhibit essentially the full range of...
	www.britannica.com /eb/article-9110300 (728 words)

	States of Matter -- Solid, Liquid, Gas, Plasma
		Amorphous solids do not have a definite melting point or regular repeating units.
		An amorphous solid is a solid in which there is no long-range order of the positions of the atoms unlike those in crystalline solids.
		Aerogels are the lightest solids and have a density of 1.9 mg per cm3 or 1.9 kg/m3 (526.3 times lighter than water).
	www.edinformatics.com /math_science/states_of_matter.htm (984 words)

	Categories of Solids
		Solids can be divided into three categories on the basis of how the particles that form the solid pack.
		Polycrystalline solids are an aggregate of a large number of small crystals or grains in which the structure is regular, but the crystals or grains are arranged in a random fashion.
		Solids can be classified on the basis of the bonds that hold the atoms or molecules together.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch13/category.php (738 words)

	Patent 6,168,805 (Site not responding. Last check: 2007-10-14)
		A process for preparing solid, amorphous paroxetine comprising: (A) mixing paroxetine free base or a pharmaceutically acceptable paroxetine salt with water and pharmaceutically acceptable polymer; and (B) drying to form a composition comprising amorphous paroxetine and polymer, eliminating the need for organic solvents common for the solvent process.
		The resultant amorphous solid paroxetine composition is free from crystalline form, and yet has good handling properties, making it suitable for pharmaceutical use in the traditional tablet dosage form.
		However, the preferred range of paroxetine in the solid dispersion is about 16% to about 50% of the total solid dispersion weight, more preferable is about 20% to about 50%, even more preferable is about 25% to about 40%, most preferable is about 33% of the total dispersion weight.
	www.pharmcast.com /Patents/January2001/6168805_SolidDispersion010201.htm (2142 words)

	General Chemistry Online: Glossary: Solids
		A solid that does not have a repeating, regular three-dimensional arrangement of atoms, molecules, or ions.
		A solid is a relatively dense, rigid state of matter, with a definite volume and shape.
		Molecules in solids are often packed close together in regularly repeating patterns, and vibrate around fixed positions.
	antoine.frostburg.edu /chem/senese/101/solids/glossary.shtml (316 words)

	Chemistry 103A; Sections 5, 6, 7, 8; Lecture 1; 21 Aug 00
		In the first four of these the structure of the solid is a regular array of ions, molecules, or atoms called a crystal.
		That is, the material remains a solid on heating until the melting point is reached and then will remain at the melting temperature until enough heat has been absorbed to melt the entire sample.
		Amorphous (which means "formless") solids do not have long range order.
	www.chem.arizona.edu /~salzmanr/103a004/nts004/l38/l38.html (703 words)

	Matterrific: States of Matter
		A solid is defined as matter with a definite shape and a definite volume.
		A solid can be made of many of the same atoms, or a mixture of atoms.
		A Crystalline solid is matter (with a definite shape and volume) that is composed of particles arranged in a repeating pattern.
	library.thinkquest.org /C0115023/states.html (386 words)

	Chapter Eight
		Some solids, such as sugar and table salt in the form in which we are most familiar, are composed of single crystals.
		Solid carbon dioxide (dry ice) is composed of molecular crystals in which CO molecules are the unit particles.
		All of the surfaces of a solid are free surfaces.
	www.3rd1000.com /chptr8.htm (2370 words)

	UW-Madison MRSEC
		Amorphous materials are formed by cooling the liquid material quickly enough to prevent crystallization; the atoms do not have time to arrange themselves into an ordered structure.
		Liquidmetal®; is an amorphous alloy (also known as a metallic glass) containing five elements, with the elemental composition is 41.2% zirconium, 22.5% beryllium, 13.8% titanium, 12.5% copper, and 10.0% nickel.
		This amorphous alloy was developed by William Johnson at Caltech in 1992.
	mrsec.wisc.edu /Edetc/background/amorphous/index.html (877 words)

	Solids (Site not responding. Last check: 2007-10-14)
		Amorphous solids are characterized by having curved faces and edges when they are broken.
		Metallic silicon would also be a covalent solid, but it is usually considered to be a semiconductor in which the band properties are the dominant feature of the bonding.
		Metallic solids are a special case because of the nature of the bonding between the atoms that make up the solid.
	neon.chem.uidaho.edu /~honors/solids.html (629 words)

	IBM Research \| Projects \| Amorphous Materials and Interfaces
		We are trying to understand the structure and properties of covalent amorphous material and their interfaces with crystalline substrate by using Monte Carlo methods.
		can be best described as continuous random network: each atom in the amorphous solid has the same number of covalent bonds as in their crystalline phase, the amorphous nature of the structure is reflected by the random network made by the covalent bonds.
		An illustrative picture of an amorphous silicon dioxide structure is shown in figure 1.We model the structure of such covalent amorphous material by a random graph (network), where the vertices of the graph represent the atoms, and the edges of the graph represent the chemical bonds.
	www.research.ibm.com /amorphous (492 words)

	Project Web -- Schedule
		In the solid, high power decoupling is necessary because of abundance of NMR active nuclei nearby, and could not average the interaction to zero.
		In solid, spin lattice relaxation is very inefficient and T1 is very long, in tens of seconds, due to the restricted motion.
		C in solids, there are no significant homonuclear couplings, since they are far away each other in the sample.
	www.emory.edu /NMR/Hall/solid/Theory_basic.htm (666 words)

	Structural Evolution in Mechanically Alloyed Al-Fe Powder Mixtures
		An inherent advantage of the MA process is that it is a solid state process, thus allowing alloying of constituent elements of significally different melting points or those which are immiscible in the solid state; which is often difficult or impossible by conventional melting techniques.
		However, in MA a metastable equilibrium is reached between the supersaturated solid solution and the amorphous phase and this limits the solid solubility.
		Accordingly an amorphous was observed in the Al3Fe composition in the present work, which is one of the boundaries of the composition range predicted by Miedema model [30] and by other investigations.
	www.tms.org /Students/Winners/Mukhopadhyay/Mukhopadhyay.html (3845 words)

	Glass is a solid(Gerald L. Hurst, Richard A. Schumacher)
		The term "amorphous solid" is oxymoronic only to the extent that it contradicts your naive notion that a material may not be simultaneously solid and have a limited range of crystalline order.
		Under the astronomical pressure of that hard tip a solid genenerates a steady counterforce at a given diameter whereas a liquid flows in such a manner as to produce a counterforce which is a function of penetration velocity.
		The most interesting amorphous phase is one made by fast neutron bombardment of just about any kind of solid SiO2; it is less dense than conventional quartz but is said to be about 2.6 percent denser than ordinary vitreous silica.
	yarchive.net /chem/glass.html (11027 words)

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