Described are devices employing a ferroelastic crystal having two spontaneous strain states separated by a zigzag domain wall which can be switched to increase one strain state at the expense of the other by motion of the zigzag wall as a whole. Zigzag walls can be created by applying high stress to ferroelastic crystals under conditions which inhibit formation of normal planar walls. Once formed the zigzag walls are stable in the absence of applied stress and can be moved through the crystal by conventional means. The use of such a device in an optical shutter is also described.
展开▼
