Determining the energetics of vicinal perovskite oxide surfaces

Werner A Wessels,Harold J W Zandvliet,Gertjan Koster,Guus Rijnders,Tjeerd R J Bollmann

doi:10.1063/1.4982886

Werner A Wessels, Harold J W Zandvliet + Show 3 more

Open Access

https://doi.org/10.1063/1.4982886

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Journal: AIP Advances	Publication Date: May 1, 2017
Citations: 1	License type: cc-by

Affiliation: University of Twente

Abstract

The energetics of vicinal SrTiO$_3$(001) and DyScO$_3$(110), prototypical perovskite vicinal surfaces, has been studied using topographic atomic force microscopy imaging. The kink formation and strain relaxation energies are extracted from a statistical analysis of the step meandering. Both perovskite surfaces have very similar kink formation energies and exhibit a similar triangular step undulation. Our experiments suggest that the energetics of perovskite oxide surfaces is mainly governed by the local oxygen coordination.

Highlights

The perovskite oxides are a fascinating class of material, due to their wealth in available physical properties, such as superconductivity, ferromagnetism, ferro- and dielectricity
The kink formation energy is an important parameter in thin film growth, facilitating nucleation during growth and thereby determining the resulting growth to be either of rough 3D or 2D stepflow character
We describe a method to determine both, the strain relaxation energy together with the step edge formation energy by the use of Atomic Force Microscopy (AFM) as it can image the surface topography irrespective of its band gap

Summary

INTRODUCTION

The perovskite oxides are a fascinating class of material, due to their wealth in available physical properties, such as superconductivity, ferromagnetism, ferro- and dielectricity. For application within oxide thin film devices, grown multilayer (perovskite) heterostructures typically contain at least one functional active layer which is directly supported onto a substrate, or with a bottom electrode layer in between film and substrate In these (ultra)thin film structures enormous strains might be beneficial, as they can result in unanticipated functional properties such as altering T c of ferromagnetic and superconducting materials.[1,2,3,4] uncontrolled strain relaxation might result in destructive cracking[5,6,7] or threading dislocation cascades[8,9,10] within thin films. We conclude by summarizing the observed findings and argue how the reported implications are anticipated to be of generic character

EXPERIMENTAL DETAILS

STATISTICAL ANALYSIS

CONCLUSIONS