Exploring transmission Kikuchi diffraction using a Timepix detector

Vespucci, S., Winkelmann, A., Mingard, K., Maneuski, D. , O'Shea, V. and Trager-Cowan, C. (2017) Exploring transmission Kikuchi diffraction using a Timepix detector. Journal of Instrumentation, 12(2), C02075. (doi: 10.1088/1748-0221/12/02/C02075)

Abstract

Electron backscatter diffraction (EBSD) is a well-established scanning electron microscope (SEM)-based technique [1]. It allows the non-destructive mapping of the crystal structure, texture, crystal phase and strain with a spatial resolution of tens of nanometers. Conventionally this is performed by placing an electron sensitive screen, typically consisting of a phosphor screen combined with a charge coupled device (CCD) camera, in front of a specimen, usually tilted 70° to the normal of the exciting electron beam. Recently, a number of authors have shown that a significant increase in spatial resolution is achievable when Kikuchi diffraction patterns are acquired in transmission geometry; that is when diffraction patterns are generated by electrons transmitted through an electron-transparent, usually thinned, specimen. The resolution of this technique, called transmission Kikuchi diffraction (TKD), has been demonstrated to be better than 10 nm [2,3]. We have recently demonstrated the advantages of a direct electron detector, Timepix [4,5], for the acquisition of standard EBSD patterns [5]. In this article we will discuss the advantages of Timepix to perform TKD and for acquiring spot diffraction patterns and more generally for acquiring scanning transmission electron microscopy micrographs in the SEM. Particularly relevant for TKD, is its very compact size, which allows much more flexibility in the positioning of the detector in the SEM chamber. We will furthermore show recent results using Timepix as a virtual forward scatter detector, and will illustrate the information derivable on producing images through processing of data acquired from different areas of the detector. We will show results from samples ranging from gold nanoparticles to nitride semiconductor nanorods.

• Item Type: Articles
• Additional Information: This work was carried out with the support of EPSRC Grant Nos. EP/J015792/1 and EP/M015181/1 and through support of a Carnegie Trust Research Incentive Grant No. 70483.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: O'Shea, Professor Val and Maneuski, Dr Dima
• Authors: Vespucci, S., Winkelmann, A., Mingard, K., Maneuski, D., O'Shea, V., and Trager-Cowan, C.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of Instrumentation
• Publisher: Institute of Physics Publishing Ltd.
• ISSN: 1748-0221
• ISSN (Online): 1748-0221
• Published Online: 27 February 2017
• Copyright Holders: Copyright © 2017 IOP Publishing Ltd
• First Published: First published in Journal of Instrumentation 12(2): C02075
• Publisher Policy: Reproduced under a Creative Commons License