Tokuhei Tagai, Holger Ried, W. Joswig
Nov 1, 1982
Citations
1
Influential Citations
16
Citations
Journal
Zeitschrift für Kristallographie - Crystalline Materials
Abstract
Petalite, LiAlSi4O10, can be interpreted as a layer silicate. Folded [Si205]-layers are linked by Li und Al tetrahedra. The crystal structure of a natural petalite was refined using neutron diffraction. The refinement of the centrosymmetric structure (space group Ρ 2/a) converged to an R factor of 3.6 % for 830 observed reflections. The site occupancies of Li, Al and Si in the tetrahedra were directly refined. The result shows that these three cations are perfectly ordered. The crystal used in neutron diffraction was also studied by transmission electron microscopy. In dark-field images, antiphase domains were observed. The antiphase vector is 5 [100] and the boundary planes are parallel to (001) and (IOT). The formation of the antiphase domains is closely related with Li and Al ordering. Oriented intergrowths of two high temperature phases and original low-petalite resulted during a heat experiment.