Domain Nucleation and Hysteresis Loop Shape in Piezoresponse Force Spectroscopy

TL;DR

This paper analyzes ferroelectric switching in Piezoresponse Force Spectroscopy by modeling electric fields and domain sizes, clarifying how domain nucleation influences hysteresis loop shapes at the nanoscale.

Contribution

It introduces a modified point charge model and derives the relationship between domain size and PFM signal, highlighting the role of domain nucleation in hysteresis behavior.

Findings

Electric field modeled with a modified point charge reproduces tip effects.

Relationship between semiellipsoidal domain size and PFM signal established.

Domain nucleation significantly affects hysteresis loop shape.

Abstract

Electromechanical hysteresis loop measurements in Piezoresponse Force Microscopy (Piezoresponse Force Spectroscopy) have emerged as a powerful technique for probing ferroelectric switching behavior on the nanoscale. Interpretation of PFS data requires the relationship between the domain parameters and PFM signal to be established. Here, we analyze the switching process using a modified point charge model for the electric field of the tip. The charge value and position are selected so that its electric field isopotential surface reproduces the tip with definite radius of curvature. Using linear theory of elasticity the relationship between the sizes of semiellipsoidal domain and PFM signal has been derived. The role of domain nucleation on piezoresponse hysteresis loop is established.