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3/6/22, 12:43 PMAmorphous solid - Wikipedia1/4Amorphous metals have lowtoughness, but high strengthAmorphous solidIncondensed matter physics andmaterials science, anamorphous(from theGreeka, "without",andmorphé, "shape, form") ornon-crystalline solidis asolid that lacks thelong-range order,which is a characteristic of acrystal. In some older articles and books, the term was usedsynonymously withglass. Today, however, "glassy solid" or "amorphous solid" is considered to bethe overarching concept, and glass is considered to be a special case: glass is an amorphous solidmaintained below itsglass transition temperature.[1]Polymers are often amorphous.[2]Amorphous materials have an internal structure comprisinginterconnected structural blocks that can be similar to thebasic structural units found in the corresponding crystallinephase of the same compound.[3]Whether a material isliquidor solid depends primarily on the connectivity between itselementary building blocks; solids are characterized by a highdegree of connectivity whereas structural blocks in fluids havelower connectivity.[4]In the pharmaceutical industry, some amorphous drugs havebeen shown to offer higher bioavailability than their crystallinecounterparts as a result of the higher solubility of theamorphous phase. However, certain compounds can undergoprecipitation in their amorphous formin vivo, and can then decrease mutual bioavailability ifadministered together.[5][6]Nano-structured materialsAmorphous thin filmsSoilsReferencesFurther readingExternal linksEven amorphous materials have some degree of short-range order at the atomic length scale as aresult of the nature of intermolecularchemical bonding (seestructure of liquids and glasses formore information on non-crystalline material structure). Furthermore, in very smallcrystals,short-range order encompasses a large fraction of theatoms; nevertheless, relaxation at thesurface, along with interfacial effects, distort the atomic positions and decrease structural order.Even the most advanced structural characterization techniques, such asx-ray diffraction andtransmission electron microscopy, have difficulty in distinguishing amorphous and crystallinestructures at short length scales.[7]ContentsNano-structured materialsAmorphous thin films
3/6/22, 12:43 PMAmorphous solid - Wikipedia2/4Amorphous phases are important constituents ofthin films, which are solid layers of a fewnanometres to some tens ofmicrometres thickness deposited upon a substrate. So-called structurezone models were developed to describe the microstructure of thin films and ceramics as afunction of thehomologous temperatureThthat is the ratio of deposition temperature overmelting temperature.

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Glass, Amorphous solid, Physics of Amorphous Materials, Physical Properties of Amorphous, Physics of Amorphous Solids

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