Atom probe tomography of a Cu-doped TiNiSn thermoelectric material: nanoscale structure and optimization of analysis conditions

He, H., Halpin, J. E., Popuri, S. R., Daly, L. , Bos, J.-W. G., Moody, M. P., MacLaren, D. A. and Bagot, P. A.J. (2021) Atom probe tomography of a Cu-doped TiNiSn thermoelectric material: nanoscale structure and optimization of analysis conditions. Microscopy and Microanalysis, (doi: 10.1017/S1431927621012162) (PMID:34315548) (Early Online Publication)

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Abstract

Cu-doping and crystallographic site occupations within the half-Heusler (HH) TiNiSn, a promising thermoelectric material, have been examined by atom probe tomography. In particular, this investigation aims to better understand the influence of atom probe analysis conditions on the measured chemical composition. Under a voltage-pulsing mode, atomic planes are clearly resolved and suggest an arrangement of elements in-line with the expected HH (F-43m space group) crystal structure. The Cu dopant is also distributed uniformly throughout the bulk material. For operation under laser-pulsed modes, the returned composition is highly dependent on the selected laser energy, with high energies resulting in the measurement of excessively high absolute Ti counts at the expense of Sn and in particular Ni. High laser energies also appear to be correlated with the detection of a high fraction of partial hits, indicating nonideal evaporation behavior. The possible mechanisms for these trends are discussed, along with suggestions for optimal analysis conditions for these and similar thermoelectric materials.

Item Type:Articles
Status:Early Online Publication
Refereed:Yes
Glasgow Author(s) Enlighten ID:Daly, Dr Luke and Halpin, Dr John and MacLaren, Dr Donald
Authors: He, H., Halpin, J. E., Popuri, S. R., Daly, L., Bos, J.-W. G., Moody, M. P., MacLaren, D. A., and Bagot, P. A.J.
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
College of Science and Engineering > School of Physics and Astronomy
Journal Name:Microscopy and Microanalysis
Publisher:Cambridge University Press
ISSN:1431-9276
ISSN (Online):1435-8115
Published Online:28 July 2021
Copyright Holders:Copyright © 2021 The Authors
First Published:First published in Microscopy and Microanalysis 2021
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
172181Nanostructured half-Heuslers for thermoelectric waste heat recoveryDonald MaclarenEngineering and Physical Sciences Research Council (EPSRC)EP/N017218/1P&S - Physics & Astronomy
172958A Focused Noble Gas Ion Beam Facility for Materials and Device Nanoanalysis - EQUIPMENT GRANTIan MacLarenEngineering and Physical Sciences Research Council (EPSRC)EP/P001483/1P&S - Physics & Astronomy