Estudo cristalográfico de berilos naturais
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2018-12-04
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Universidade Federal de Goiás
Resumo
The crystallography is for excellence the methodology that presents itself as the most
adequate for structural elucidation due to the high resolution with which it can be described
the electronic density, besides being a methodology that brings with it an interdisciplinary
character, crossing the various cognitive areas, corroborating to the state of the art together
with the demand for new technologies that come to enter the development of science. In this
job are presented the crystallographic studies of 13 crystalline samples of beryl, being 2
samples of acquamarine and 11 industrial beryl, being 1 octahedral sample, in other words,
there is a total or partial replacement of Al by some metal, 1 sample in transition from the
octahedral type to normal, 3 samples of the normal type, without any type of atomic
substitution, 5 transition samples of the normal type for tetrahedra and 2 tetrahedra samples,
that is, with total or partial replacement of the Be for Li. Was performed with data sets
obtained by X-ray diffraction of monocrystal and complemented with the method of Sum of
the Bond Valence Model and Fingerprints. The results showed that through the analysis of the
lattice parameters of the samples it was possible to determine the typology of each one
through the c/a ratio. Axis a had changes in the 13 diffracted monocrystals, varying between
9,2054Å and 9,2400Å. The c axis showed a slightly more significant variation, its values
remained between 9,1791Å and 9,2200Å. The Bond Valence Model was used to indicate
possible ions in the structures and their oxidation states. Fingerprints were used to quantify
the contribution of each interatomic contact to the stability of the structures. All samples were
similar, diverging in small configurations according to the typology and their respective
substitutions and inclusions.
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PAULA, R. L. G. Estudo cristalográfico de berilos naturais. 2018. 164 f. Dissertação (Mestrado em Fisica) - Universidade Federal de Goiás, Goiânia, 2018.