High temperature crystal structure of a 3 : 2 mullite from neutron diffraction data
Zeitschrift Fur Kristallographie 216(5): 284-290
| Autoren/Herausgeber: |
Brunauer G Boysen H Frey F Hansen T Kriven W |
|---|---|
| Erschienen: | 2001 |
High temperature neutron investigations up to 1950 K of 3:2-sintered mullite show a smooth reversible behaviour which can be described by a rotation of more or less rigid TO4 (T = Al(2),Si)-tetrahedra and accompanying distortions of the Al(l)O-6-octahedra. Large atomic displacement parameters along the c-direction, including static parts, match to respective structural modulations in the mullite structure. A comparison of a pristine and a preheated sample reveals an irreversible depopulation of the Al(2) atomic site in favour of the Al(*) site.