Date: Wednesday 7th of November 2018, 14:00.
Location: DCB1105 (David Chiddick Building).

‘Structure and properties of extended defects in materials through first principles calculations and electron microscopy’

by Keith McKenna, Department of Physics, University of York, York, UK.

Abstract:

Semiconducting and insulating materials are ubiquitous in nature and find diverse applications in technology. Such materials are normally polycrystalline and contain extended defects such as grain boundaries and dislocations that can affect their properties. While the role of such defects on mechanical properties is relatively well understood their impact on electronic, optical, magnetic or chemical properties is far less clear and challenging to probe experimentally. In this talk I will present some of our recent work on modelling the structure and properties of extended defects in a range of materials of practical and fundamental interest using first principles methods. These materials include TiO2 [1], MgO [2-4], Fe3O4 [5,6], formamidinium lead iodide [7] and Cu2ZnSnSe4 [8] and in each case links to complementary experimental transmission electron microscopy investigations will be highlighted.

[1] E. Maras et al, Acta Materialia 163, 199 (2018)
[2] Z-C. Wang et al, Nature 479, 380-383 (2011)
[3] Z-C. Wang et al, Nature Communications 5, 3239 (2014)
[4] K. P. McKenna et al, Nature Communications 5, 5740 (2014)
[5] D. Gilks et al, Scientific Reports 6, 20943 (2016)
[6] J. J. Bean et al, Scientific Reports 7, 45594 (2017)
[7] K. P. McKenna, ACS Energy Letters 3, 2663 (2018)
[8] B. Mendis et al, Journal of Materials Chemistry A 6, 189 (2018)