Ferroelectric ceramic memory devices

This paper discusses the information storage characteristics of an improved lead zirconate-lead titanate ferroelectric ceramic composition. The memory elements discussed are ceramic disc resonators operated in the radial extensional mode and utilizing small-signal, nondestructive readout of the remanent polarization state. Fabrication procedure and design considerations such as the effect of electrode geometry are discussed and an approximate equivalent circuit of a multibit memory element is presented. Device charactristics such as complex transfer characteristics, dependence of small-signal parameters on polarization state, and temperature effects are given. Various methods of information read-in and readout are discussed. Possible applications of this memory include moderate speed computing systems, long-term information storage, and use in extreme environmental conditions.