On the reliability of highly magnified micrographs for structural analysis in materials science

Martin Wortmann,Uwe Kahmann,Andrea Ehrmann,Natalie Frese,Jacek Grzybowski,Jan Lukas Storck,Tomasz Blachowicz,Timo Grothe,Ashley Stephen Layland,Bruno Hüsgen

doi:10.1038/s41598-020-71682-8

Abstract

Highly magnified micrographs are part of the majority of publications in materials science and related fields. They are often the basis for discussions and far-reaching conclusions on the nature of the specimen. In many cases, reviewers demand and researchers deliver only the bare minimum of micrographs to substantiate the research hypothesis at hand. In this work, we use heterogeneous poly(acrylonitrile) nanofiber nonwovens with embedded nanoparticles to demonstrate how an insufficient or biased micrograph selection may lead to erroneous conclusions. Different micrographs taken by transmission electron microscopy and helium ion microscopy with sometimes contradictory implications were analyzed and used as a basis for micromagnetic simulations. With this, we try to raise awareness for the possible consequences of cherry-picking for the reliability of scientific literature.

Highlights

Magnified micrographs are part of the majority of publications in materials science and related fields
Related issues regarding material characterization have been discussed by Linford et al in the context of X-ray photoelectron s pectroscopy[8] and by Anderson et al using the example of nanoparticle analysis by transmission electron microscopy (TEM)[9]
Our paper discusses how the selection of micrographs can significantly influence their implications, based on sets of TEM and helium ion microscopy (HIM) images taken on identical samples of poly(acrylonitrile) (PAN) nanofiber nonwovens with embedded nickel-ferrite and magnetite nanoparticles

Summary

Introduction

Magnified micrographs are part of the majority of publications in materials science and related fields. They are of essential importance for the evaluation of research results up to the point where the entire conclusion of a paper depends on the quality of the selected micrographs.

Results

Conclusion