X-ray Topographic Investigation of Quartz Single Crystals at High Temperature, up to 1185DGC

Real time experiments were performed to study the structural behaviour of monocrystalline quartz at high temperatures. White beam diffraction topography in transmission geometry was used. A creation of Dauphine-twins took place slightly below the -phase transition temperature. The diffraction contrast of twins and temperature stresses disappeared above the -phase transition temperature. Up to 1185DGC neither changes of the defect structure nor a creation of new defects were observed. A precursor for a beginning of a reconstructive phase transition from quartz to cristabolite could not be observed within a time interval of 2h at 1180DGC.