Fundamental study on ferroelectric data storage with the density above 1 Tbit/inch2 using congruent lithium tantalate

Ferroelectrics have created considerable interest as promising storage media. In this paper, an investigation for ultra high-density ferroelectric data storage based on scanning nonlinear dielectric microscopy (SNDM) was carried out. For the purpose of obtaining the fundamental knowledge of high-density ferroelectric data storage, several experiments of nano-domain formation in lithium tantalate (LiTaO₃) single crystal were conducted. As a result, domain dot array with areal density of 1.5 Tbit/inch² was written in congruent LiTaO₃ (CLT). We also found that quite fast nano second domain switching was possible by reducing a sample thickness even in CLT with a lot of Li vacancy defects which played a role of pinning sites against domain wall movement.