Low-voltage nanodomain writing in He-implanted lithium niobate crystals

TL;DR

This study demonstrates low-voltage writing of stable ferroelectric domains in He-implanted lithium niobate crystals using a scanning force microscope, revealing a buried non-ferroelectric layer that acts as a barrier to domain growth.

Contribution

It introduces a method for low-voltage ferroelectric domain writing in lithium niobate by exploiting a buried non-ferroelectric layer created through helium implantation.

Findings

Stable surface domains < 1 μm written with only 10 V pulses.

Buried He-implanted layer acts as a barrier to domain growth.

Domains can be written in 500 μm-thick substrates.

Abstract

A scanning force microscope tip is used to write ferroelectric domains in He-implanted single-crystal lithium niobate and subsequently probe them by piezoresponse force microscopy. Investigation of cross-sections of the samples showed that the buried implanted layer, $\sim 1$\,\textmu m below the surface, is non-ferroelectric and can thus act as a barrier to domain growth. This barrier enabled stable surface domains of $< 1$\,\textmu m size to be written in 500\,\textmu m-thick crystal substrates with voltage pulses of only 10\,V applied to the tip.