Monolithic Electronic Devises Based on Domain Wall Motion in a Ferroeletric Crystal

A variety of electronic functions can be accomplished in a novel way by taking advantage of the properties of domain wall motion in ferroelectric single crystals. Using lead germanate, an elementary gating/amplifying device and a simple analog read-only memory have been demonstrated. 1 Using gadolinium molybdate, a much more complicated analog read-only memory capable of storing four seconds of speech waveforms has been produced. 2 The theory of several other wall motion devices, including image scanners and logic gates, has been investigated. These latter devices have not been demonstrated but rely on the same principles as those which have. The purposes of this paper are (i) to summarize the basic concepts common to all the above devices, (ii) to discuss material problems and requirements as they relate to improving the devices already demonstrated and to realizing the undemonstrated ones, and (iii) to describe specific device configurations using presently available materials and to show configurations achievable with improved materials.