The monoclinic-hexagonal phase transition in chlorapatite
Bauer, Michael; Klee, Wilfrid E.
European Journal of Mineralogy Volume 5 Number 2 (1993), p. 307 - 316
published: Apr 27, 1993
manuscript accepted: Nov 30, 1992
manuscript received: Mar 18, 1992
ArtNo. ESP147050502016, Price: 29.00 €
Abstract The phase transition in chlorapatite from the monoclinic ferroelastic to the hexagonal paraelastic phase has been investigated with X-ray and synchrotron-radiation diffraction as well as optical and thermal methods. In the ferroelastic phase the spontaneous strain is 0.40-103 at room temperature and 0.26-103 at 192 °C. The birefringence ⟂ c was found to disappear at about 330 °C. According to the DTA measurements the transition occurs near 350 °C and is weakly discontinuous