Ultrahigh-density ferroelectric data storage based on scanning nonlinear dielectric microscopy

Ferroelectrics have generated considerable interest as promising storage media. In this paper, an investigation of ultrahighdensity ferroelectric data storage based on scanning nonlinear dielectric microscopy (SNDM) is described. For the purpose of obtaining fundamental knowledge on high-density ferroelectric data storage, several experiments on nanodomain formation in a lithium tantalate (LiTaO₃) single crystal were conducted. As a result, a very small inverted domain with a radius of 6nm was successfully formed in stoichiometric LiTaO₃ (SLT), and a domain dot array with an areal density of 1.5 Tbit/in.² was formed on congruent LiTaO₃ (CLT). Moreover, it was fou nd that fast nanosecond domain switching could be achieved by reducing the thickness of a CLT plate sample. Additionally, the prototype high-density ferroelectric data storage system was developed. Using this system, writing data transfer rates were evaluated and 256 × 256 bit data were recorded with the areal densities of 258 and 717 Gbit/in.².