Abstract: Methods and devices are described for driving ferroelectric perovskite oxide crystals to achieve polarization inversion with reduced coercivity. In some embodiments, the anisotropy in the potential energy surface of a ferroelectric material is employed to drive polarization inversion and switching with a reduced coercive field relative to uniaxial excitation. In some embodiments, polarization inversion with reduced coercivity is produced via the application of an electric field that exhibits a time-dependent orientation, in contrast with conventional uniaxial electrical excitation, thereby causing the central ion (and the crystal structure as a whole) to evolve along a lower-energy path, in which the central ion is driven such that it avoids the potential energy maximum. This may be achieved, for example, by applying at least two non-parallel time-dependent voltages (e.g. bias, potential) such that orientation of the electric field changes with time during the switching cycle.

Abstract: PbO-based photoconductive X-ray imaging devices are disclosed in which the PbO photoconductive layer exhibits an amorphous crystal structure. According to selected embodiments, the amorphous PbO photoconductive layer may be formed by providing a substrate inside an evacuated evaporation chamber and evaporating lead oxide to deposit a photoconductive lead oxide layer onto the substrate, while subjecting the photoconductive layer to ion bombardment with oxygen ions having an ion energy between 25 and 100 eV. X-ray direct detection imaging devices formed from such amorphous PbO photoconductive layers are shown to exhibit image lag that is suitable for fluoroscopic imaging.