Amorphous bodies

A. Guinier, Diffraction In Crystals, Imperfect Crystals, and Amorphous Bodies, Dover, New York, 1963. 

A. Guinier, X-Ray Diffraction In Crystals and Amorphous Bodies, Freeman, San Francisco, 1964. 

The electrode material plays an important, although little understood role for the outcome or organic electrosyntheses. Innumerable reports (see e.g. Swann, 1956) bear witness to much painstaking work on electrode preparation and pretreatment, sometimes to an extent that one despairs of ever getting any order in this vast, amorphous body of know-how. Just to take one example, it has been reported that the temperature at which a certain solid electrode was cast had a marked effect upon product distribution (Swann et al., 1966) ... 

The excess of volume is one of the most important features which distinguishes the amorphous from the crystalline state of matter of the same chemical structure. In an amorphous body, one can observe some excess volume which exists in the form of free volume and plays the key role in the kinetic properties of the body 38). 

This can only be decided by experiment, or, failing that, by a suitable hypothesis whose consequences are in agreement with experiment. Properties which appear to approach infinity at the absolute zero are, for example, the electrical and thermal conductivity of metals and the thermal conductivity of crystals (Eucken ), while the thermal conductivity of amorphous bodies, the specific heat, and the coefficient of expansion appear to approach zero. 

Franchimont [67], who could obtain santalin only in an amorphous state, ascribes to it the formula C17H13O6. On heating with hydrochloric acid to 200°, he obtained methyl chloride and an amorphous body (CaHigOg ), which gives a violet-black solution with alkalies. 

A study of the proeess by which orcein is formed from lichens, by action of ammonia and air, shows that three colouring-matters are formed, viz., orcein, a yellow crystalline compound, and an amorphous body resembling litmus. 

Glusker JP, Traeblood KN (1985) Crystal Stmctnre Analysis. 2nd edition. Oxford Univ Press, Oxford, UK Gnutzmaim V, Vogel W (1990) Surface oxidation and reduction of small platinum particles observed by in situ X-ray diffraction. Z PhysikD (Atoms, Molecules, Clusters) 12 597-600 Greenwood NN (1970) Ionic Crystals Lattice Defects and Norrstoichiometry. Butterworths, London Guinier A (1963) X-ray Diffraction in Crystals, Imperfect Crystals, and Amorphous Bodies. W H Freeman, San Francisco... 

G,21 A. Guinier. X-Ray Diffraction in Crystals, Imperfect Crystals, and Amorphous Bodies (San Francisco W. H, Freeman, 1963). Largely theoretical and more advanced than [G.IO]. 

On account of the fact that all grades of rigidity have been realised between the ordinary solid and the liquid state, in the case both of crystalline and of amorphous substances, it has been proposed to abandon the terms solid and liquid, and to class bodies as crystalline or amorphous, the passage from the one condition to the other being discontinuous crystalline bodies possess a certain regular orientation of their molecules and a directive force, while in amorphous bodies these are wanting (see Lehmann, Annalen d. Physik, 1900 [4], 2,696). See, however, von K Iioid Z, 1908,3, 282 1909,4, 27, 123, 198, 252, 315 5, 62, ny, 150, 212, Poster, ibid, 1910, 7, 29. 

A. F. Skrishevskii, Structure analysis of liquids and amorphous bodies, Fligh school, Moscow, 1980. 

Guinier A (1994) X-ray diffraction in crystals, imperfect crystals and amorphous bodies. Dover, New York... 

Franks, N.P. and Lieb, W.R. (1976)/. Mol Biol, 133,469. Guinier, A. (1963) X-ray Diffraction Analysis in Crystals. Imperfect Crystals and Amorphous Bodies, Freeman, London. 

Grinding or any other deformation of a solid causes crushing and disorganization of crystal grains, generation of defects, dislocations, micro-cracks, and ultimately amorphization of the crystalline material. The question arises to what size it is possible to grind a crystal in order for its properties still to correspond to those of the bulk material, and where is the size border between a crystal and an amorphous body ... 

Dispersing polycrystalline substances can produce such grains that their properties will differ from those of bulk materials Roy was the first to consider this question [1], He concluded that the minimum size of a particle which shows properties of the bulk crystal, according to various physical methods, must exceed 10 nm. Such materials now are called nano-materials (1 nm = 10 A). Roy stated that the same amorphous body can have a different short-range atomic order, for example amorphous Si02 prepared by different methods has different properties. 

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