Overcoming Challenges Associated with the Analysis of Nacre by Atom Probe Tomography

Abstract

In this study atom probe tomography was used to study nacre, an important biocomposite material that is challenging to prepare and analyse by atom probe and, when successful, yields data that is challenging to interpret. It was found that these challenges mainly arise from the insulating and heterogeneous nano‐scale properties of nacre. We outline our current best practice for preparing and running atom probe tips, such as using a low acceleration voltage (< 3 kV) and current (≤ 50 pA) to avoid damage to the microstructure, and using transmission electron microscopy to confirm that the region of interest is located close to the apex of the atom probe tip. Optimisation of the preparation parameters led to several successful atom probe experiments, with one of the data sets containing part of an organic membrane and others showing organic inclusions within the reconstruction.

Nanoscale Chemical Imaging by Photo‐Induced Force Microscopy: Technical Aspects and Application to the Geosciences

“…2017, Eder et al . 2019). As PiFM imaging is performed at ambient conditions, materials that are unstable in vacuum can be analysed and experiments can be performed immediately after sample mounting.…”

“…One of the challenges for unravelling the detailed mechanisms of their formation is associated with the nature of this material, which is electron‐beam‐sensitive, insulating, delicate and hydrous (Eder et al . 2019).…”

“…2009, Eder et al . 2019); however, neither method is able to provide insight into the specific phase composition. The identification of proteinaceous amides within organic inclusions is particularly valuable as compound information on organic phases has previously only been possible to obtain via bulk FTIR or SS‐NMR analysis after extensive purification treatments that dissolve the mineral phase and allow for the separate investigation of soluble and insoluble organic phases (e.g., Agbaje et al .…”

Guest Editorial: Special Issue Based on the 2018 IAG Geoanalysis Conference

“…Eder et al . () detail their successful method for analysis of nacre (the iridescent material commonly known as mother‐of‐pearl) by atom probe tomography to overcome challenges mainly caused by nano‐scale heterogeneities, related to sample preparation, analysis and data interpretation. Wang et al .…”

“…They showed that a modified grinding technique allowed reliable results to be obtained for small test portion masses. Eder et al (2019) detail their successful method for analysis of nacre (the iridescent material commonly known as mother-of-pearl) by atom probe tomography to overcome challenges mainly caused by nano-scale heterogeneities, related to sample preparation, analysis and data interpretation. Wang et al (2019) detail their improved procedure for analysis of Os isotope ratios from exceedingly small samples, using new 10 13 Ω pre-amplifier technology in TIMS, and applied their procedure to geological RMs with low Os mass fractions.…”