Complementary SEM-AFM of Swelling Bi-Fe-O Film on HOPG Substrate

Dinara Sobola,Shikhgasan Ramazanov,Alexandr Knápek,Pavel Kaspar,Martin Konečný,Farid Orudzhev,Nikola Papež,Michal Potoček

doi:10.3390/ma13102402

Abstract

The objective of this work is to study the delamination of bismuth ferrite prepared by atomic layer deposition on highly oriented pyrolytic graphite (HOPG) substrate. The samples’ structures and compositions are provided by XPS, secondary ion mass spectrometry (SIMS) and Raman spectroscopy. The resulting films demonstrate buckling and delamination from the substrates. The composition inside the resulting bubbles is in a gaseous state. It contains the reaction products captured on the surface during the deposition of the film. The topography of Bi-Fe-O thin films was studied in vacuum and under atmospheric conditions using simultaneous SEM and atomic force microscopy (AFM). Besides complementary advanced imaging, a correlative SEM-AFM analysis provides the possibility of testing the mechanical properties by using a variation of pressure. In this work, the possibility of studying the surface tension of the thin films using a joint SEM-AFM analysis is shown.

Highlights

The combination of bismuth ferrite (BFO) and highly oriented pyrolytic graphite (HOPG) has potential in the preparation of thin films with a magnetoelectric effect and an electrode in the form of multi-layer graphene [1,2]
Figure showsincreased increased the at at thethe surface according to thetoSIMS
An increased interest in multiferroics led the researchers to investigate their combination with other prospective materials

Summary

Introduction

The combination of bismuth ferrite (BFO) and highly oriented pyrolytic graphite (HOPG) has potential in the preparation of thin films with a magnetoelectric effect and an electrode in the form of multi-layer graphene [1,2]. The symmetry of bismuth ferrite allows the existence of a linear magnetoelectric effect. The observation of the magnetization in bulk samples is impossible because of the presence of a spatially modulated spin structure. The destruction of this feature can be achieved by both the replacement of bismuth ions by isovalent cations and the preparation of thin films [4,5,6]. Atomic layer deposition (ALD) was reported to be a reliable method for BFO deposition on silicon oxide/platinum (from Ferrocene (Fe(Cp)2 ) and Bi-triphenyl (Bi(ph)3 ) precursors) [7,8], on zinc oxide (from Bismuth (III) 2,3-dimethyl-2-butoxide and iron (III)

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