ABSTRACT
The diffuse-phase-transition class of ferroelectric materials allows the fabrication of films graded in composition: the consequence of which is an attendant gradient in electric dipole moment density. Alternating electric-field excitation of these graded structures reveal an asymmetrical hysteresis characteristic, together with a static displacement of the hysteresis trace. This displacement bias is observed to be a function of excitation level and temperature, which leads to a giant effective pyroelectric coefficient. Said displacement, for example, pro vides a continuous open-circuit voltage, or short-circuit current, provided that the structure is held in an isothermal condition. All other combinations of heat, electrical and strain energies suggest a whole new class of devices, and invite ingenious concepts and/or contributions.
