Monoclinic deformation of calcite crystals at ambient conditions
Abstract
High resolution synchrotron radiation powder diffraction shows that the average crystal structure of calcite at ambient conditions is described with the trigonal space group R 3 bar c but there is a systematic hkl-dependent Bragg peak broadening. A modelling of this anisotropic peak broadening with the microstrain model from Stephens (1999) [15] is presented. The observed lattice parameters' correlations can be described by assuming a monoclinic-type deformation of calcite crystallites. A quantitative model of this monoclinic deformation observed at ambient conditions is described with the space group C 2 / c . The monoclinic unit cell suggested at ambient conditions is related with the monoclinic unit cell reported in calcite at high pressure (Merrill and Bassett (1975) [10]).
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- September 2016
- DOI:
- 10.1016/j.physb.2016.05.002
- Bibcode:
- 2016PhyB..496...49P
- Keywords:
-
- Calcite;
- CaCO<SUB>3</SUB>;
- Symmetry;
- X-ray diffraction;
- Synchrotron radiation;
- Microstrains