Observation of ferrobielastic twinning in GaPO/sub 4/ under uniaxial stress

The phenomenon of ferrobielastic twinning stimulated by uniaxial pressure is optically observed in quartz-like material GaPO/sub 4/. For X-cut samples interdomain boundaries were detected at the pressure level 350 MPa applied at the angle 45/spl deg/ with respect to Z axis. In similar experiments with AlPO/sub 4/ domain boundaries were not observed.