Construction method of high-density polarized topological domain array

Abstract

The invention discloses a construction method of a high-density polarized topological domain array, and belongs to the technical field of micro-nano structures. A bismuth ferrite film is grown througha laser pulse deposition technology, and the bismuth ferrite material does not contain lead and is a green and environment-friendly material. Through the deposition condition of low oxygen pressure,spontaneous existence of defects (such as oxygen vacancies and the like) is ensured. Under the action of a needle tip electric field of a piezoelectric microscope, the electrified defect can generatedirectional movement, and a spontaneously-existing polarization topological domain structure is influenced, so that a high-density central polarized topological domain array with the adjustable size is constructed through the needle point electric field, the size of a single topological domain is dozens of nanometers, and the polarized topological domains are controllable in overturning, good in stability and suitable for preparing a high-density ferroelectric random access memory. According to the preparation method, the pulse laser deposition technology is mature, no extra template assistance is required for preparation of a thin film, and the vector piezoelectric microscopic technology based on a scanning probe microscope is easy to operate and highly practical.

Description

technical field [0001] The invention belongs to the technical field of micro-nano structures, and in particular relates to a method for constructing a high-density polarized topological domain array. Background technique [0002] Ferroelectric memory may become the next generation of non-volatile memory and has attracted widespread attention. It has low power consumption, fast writing, much larger erase and write cycles (3.3V more than 10 16 Times) and other advantages, the disadvantage is low storage density. In recent years, as people's requirements for device miniaturization have become stronger, the market has shown eager expectations for high-density memory devices. Ferroelectric random access memory based on polarized topological domains is a representative of such high-density memory devices. In 2004, it was theoretically predicted that the size of a single vortex-polarized topological domain is 3.2nm, and the corresponding storage density reaches 60Tb / inch 2 Late...

AI Technical Summary

Problems solved by technology

At present, ferroelectric storage based on polarized topological domains faces two major challenges. One is to find green and environmentally friendly materials with simple preparation processes, and the other is to control the flipping of high-density polarized topological domains.

In 2017, people in PbTiO 3 / SrTiO 3 The controllable flipping of the ferroelectric / vortex coexisting phase is realized in the superlattice of PbTiO 3 Contains volatile lead, which is toxic

X-ray diffraction characterization can obtain information about the lattice orientation, but the visualization is not strong

Transmission electron microscope characterization can reveal the polarization direction through the inclination of the unit cell, but it can only give data of a certain cross-section of the sample, and sample preparation and characterization are destructive to the sample

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