Glass disordered atomic structure

Of the various physical properties, it is the mechanical properties that make metallic glasses so unique when compared to their crystalline counterparts. A metallic glass obtains its mechanical strength in quite a different way from crystalline alloys. The disordered atomic structure increases the resistance to flow in metallic glasses so that these materials approach their theoretical strength, An attractive feature is that metallic glasses are equally strong in all directions because ul the random order of their atomic structure... 

Using evidence presented in this demonstration, explain why crystalline solids have uniform atomic structures and glasses have disordered atomic structures. 

Arising from their disordered atomic structure and unique glass-to-supercooled liquid transition, amorphous alloys represent a new class of structural and functional materials with excellent properties (Eckert et al., 2007 Inoue, 2000 Johnson, 1999 Suryanarayana Inoue, 2011 Wang, 2009 Xu et al., 2010), e.g. high strength about 2-3 times of their... 

In this section we discuss some disordered magnetic systems that do not fit well under any of the subject headings of the other sections in this review. am-DyAg (sect. 8.3.1) is the only amorphous f-moment material studied with [iSR to date, as the pyrochlores (sect. 8.3.2) are the only perfectly fhistrated f-magnets studied with p,SR. Quasicrystals (sect. 8.3.3) must stand somewhat separately because they have atomic structure that is neither amorphous nor merely disordered-crystalline. For a discussion of spin-glass-like behavior in Ce, Yb, and U strongly correlated electron materials, see sect. 9. 

The variation of the Chin-Gilman parameter with bonding type means that the mechanism underlying hardness numbers varies. As a result, this author has found that it is necessary to consider the work done by an applied shear stress during the shearing of a bond. This depends on the crystal structure, the direction of shear, and the chemical bond type. At constant crystal structure, it depends on the atomic (molecular volume). In the case of glasses, it depends on the average size of the disorder mesh. 

In amorphous solids there is a considerable disorder and it is impossible to give a description of their structure comparable to that applicable to crystals. In a crystal indeed the identification of all the atoms in the unit cell, at least in principle, is possible with a precise determination of their coordinates. For a glass, only a statistical description may be obtained to this end different experimental techniques are useful and often complementary to each other. Especially important are the methods based on diffraction experiments only these will be briefly mentioned here. The diffraction pattern of an amorphous alloy does not show sharp diffraction peaks as for crystalline materials but only a few broadened peaks. Much more limited information can thus be extracted and only a statistical description of the structure may be obtained. The so-called radial distribution function is defined as ... 

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