Influence of multiple detection events on compositional accuracy of TiN coatings in atom probe tomography

Maximilian Schiester, Helene Waldl, Marcus Hans, Mattias Thuvander, Daniel Primetzhofer, Nina Schalk, Michael Tkadletz

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung


The accuracy of composition measurements by atom probe tomography is often dependent on the selected operation mode as well as the applied measurement parameters. The detected hit characteristics, distinguishing between single and multiple events, along with the electric field, are also affected by parameter selection. In this study, atom probe tomography experiments were performed on a stoichiometric TiN coating in voltage as well as in laser-assisted mode with systematically varied laser pulse energies. The observed elemental compositions were compared with complementary ion beam analysis measurements. The influence of multiple detection events was investigated by two approaches: I) A modified local electrode served as a hardware filter, reducing multiple detection events from 78.8 % to 41.9 % and from 40.9 % to 5.6 % using voltage mode and laser-assisted APT (0.6 nJ), respectively, and II) unfiltered datasets were analyzed by data post processing. The latter allowed the study of ion species, particularly of emerging complex molecular ions associated with dissociation processes. Additionally, average electric fields were estimated and spatial considerations were made to investigate the evolution of charge state ratios and hit characteristics during the measurement. Filtering the measurements significantly improved the elemental accuracy. In voltage mode, hardware and software filtering reduced the discrepancy between reference and observed composition from 3.8 at.% to 2.1 at.% and 0.1 at.% within uncertainty limits. In laser-assisted mode, higher laser pulse energy increased the difference between unfiltered data and the reference composition, from 1.4 at.% (0.1 nJ) to 8.1 at.% (2.0 nJ). Ion species analysis of the datasets shows an increasing presence of complex ions (Ti 2N) with raising laser pulse energy. Electric field studies reveal a decline from 40 V/nm in voltage mode to 36 V/nm applying a high laser pulse energy of 2.0 nJ, indicating insufficient field strength for neutral nitrogen re-ionization.

FachzeitschriftSurface & coatings technology
Ausgabenummer15 February
Frühes Online-Datum17 Dez. 2023
PublikationsstatusVeröffentlicht - 15 Feb. 2024

Bibliographische Notiz

Funding Information:
The authors want to thank Christian Saringer for his contribution to programming the scripts. The authors gratefully acknowledge the financial support under the scope of the COMET program within the K2 Center “Integrated Computational Material, Process and Product Engineering (IC-MPPE)” (Project No 886385 ). This program is supported by the Austrian Federal Ministries for Climate Action, Environment, Energy, Mobility, Innovation and Technology (BMK) and for Labour and Economy (BMAW), represented by the Austrian Research Promotion Agency (FFG), and the federal states of Styria, Upper Austria and Tyrol. The financial support by the Austrian Federal Ministry for Digital and Economic Affairs and the National Foundation for Research, Technology and Development is gratefully acknowledged. The financial support by the Austrian Federal Ministry of Labour and Economy , the National Foundation for Research, Technology and Development and the Christian Doppler Research Association is gratefully acknowledged. Transnational access to the ion beam analysis facility at Uppsala University has been supported by the RADIATE project under the Grant Agreement 824096 from the EU Research and Innovation program HORIZON 2020 . Accelerator operation at Uppsala University has been supported by the Swedish research council VR-RFI (# 2019-00191 ).

Publisher Copyright:
© 2023 The Authors

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