Contrast Mechanisms for the Detection of Ferroelectric Domains with Scanning Force Microscopy

TL;DR

This paper analyzes how ferroelectric domains are detected using scanning force microscopy, identifying three distinct contrast mechanisms related to piezoelectric responses and electrostatic interactions, with detailed analysis of their contributions.

Contribution

It provides a comprehensive analysis of contrast mechanisms in SFM for ferroelectric domains, clarifying the roles of piezoelectric and electrostatic effects on all crystal faces.

Findings

Three contrast mechanisms identified: out-of-plane piezoresponse, in-plane piezoresponse, electrostatic tip-sample interaction.

Analysis of cantilever movement allows clear attribution of contrast sources.

Method applicable to all faces of bulk ferroelectric crystals.

Abstract

We present a full analysis of the contrast mechanisms for the detection of ferroelectric domains on all faces of bulk single crystals using scanning force microscopy exemplified on hexagonally poled lithium niobate. The domain contrast can be attributed to three different mechanisms: i) the thickness change of the sample due to an out-of-plane piezoelectric response (standard piezoresponse force microscopy), ii) the lateral displacement of the sample surface due to an in-plane piezoresponse, and iii) the electrostatic tip-sample interaction at the domain boundaries caused by surface charges on the crystallographic y- and z-faces. A careful analysis of the movement of the cantilever with respect to its orientation relative to the crystallographic axes of the sample allows a clear attribution of the observed domain contrast to the driving forces respectively.