Mechanism-Resolved PFM of Ferroionic and Ferroelectric Responses in Thickness-Gradient Hf0.5Zr0.5O2 Libraries

TL;DR

This paper presents a systematic approach combining thickness-gradient libraries with automated scanning probe microscopy to analyze growth mechanisms and distinguish ferroelectric from electrochemical effects in Hf0.5Zr0.5O2 thin films.

Contribution

It introduces a high-throughput, automated framework for mechanism-resolved characterization of ferroionic and ferroelectric responses in complex oxide thin films.

Findings

Electrochemical activity causes irreversible topographic deformation.

Reversible phase inversion indicates ferroelectric switching.

Improved plume stabilization enhances ferroelectric phase formation.

Abstract

Resolving growth mechanisms and thickness evolution of functional properties is one of the key tasks in materials discovery and optimization involving thin-film materials, traditionally requiring significant experimental budgets. Here we introduce the combination of thickness-gradient libraries and automated scanning probe microscopy as a systematic pathway to elucidate growth modes and disentangle ferroelectric and electrochemical contributions in ferroelectric thin films. As a model system, we explore the Hf0.5Zr0.5O2 (HZO) gradient thin films grown on LaxSr1-xMnO3 (LSMO) bottom electrode thin films. Automated piezoresponse force microscopy, spectroscopy, and lithography reveals that irreversible topographic deformation arises from electrochemical activity at the LSMO surface, whereas reversible phase inversion in HZO reflects ferroelectric switching. Automated topography height-map scans are used to further quantify nucleation density, particle-size evolution, and roughness correlations across the thickness-gradient, demonstrating that improved plume stabilization during growth suppresses interfacial reactions and promotes dense, fine-grained HZO conducive to ferroelectric phase formation. This combined materials-engineering and automated-SPM framework establishes a platform for high-throughput, mechanism-resolved characterization of ferroionic and ferroelectric responses in complex oxide films.