Free-standing Graphene as Gold Standard

TL;DR

This paper introduces free-standing graphene sheets as a new, highly accurate mass standard for STEM-based mass spectrometry, enabling precise calibration and measurement of electron mean free path with atomic layer sensitivity.

Contribution

It presents a novel use of graphene sheets as a calibration standard in STEM, improving accuracy and enabling detailed analysis of complex carbon nanoparticles.

Findings

Graphene sheets serve as an effective mass standard in STEM.

Calibration accuracy is enhanced over extended thickness ranges.

The method allows measurement of electron mean free path with atomic layer precision.

Abstract

We demonstrate using graphene sheets as a novel mass standard in the scanning transmission electron microscopy (STEM) based mass spectrometry. Here, free-standing graphene sheets are investigated by STEM. The discrete number of graphene layers enables an accurate calibration of STEM intensity, as performed over an extended thickness and with single atomic layer sensitivity. This leads to the direct and accurate measurement of the electron mean free path. As an application, we gain the insight of carbon nanoparticles of complex structure.