School of Physical and Chemical Sciences Te Kura Matū Seminar Series

Monolayer oxides

Speaker

Professor Martin R. Castell Erskine Visitor with Simon Brown’s team

Institute

Department of Materials, University of Oxford, U.K.

Time & Place

Fri, 21 Feb 2020 11:00:00 NZDT in Room 112, Beatrice Tinsley Building Level 1

All are welcome

Abstract

Oxides that are created as ultrathin films have electronic, optical, magnetic and chemical properties that may be quite different from their bulk crystal counterparts. This is because of the strong interaction between the oxide film and the substrate that it is grown on. Many ultrathin metal oxide films that are only a few atomic layers thick should be considered as 2D hybrid structures - part bulk, part interface, and part surface. This talk introduces ultrathin oxides with a focus on the effect that the substrate plays on stabilizing certain structures and then concentrates in detail on the work we have carried out on TiOx and NbOx ultrathin films on Au(111) substrates. I will concentrate mainly on our scanning tunneling microscopy (STM) studies of these materials systems, but will also show some experimental results obtained using LEED, AES, XPS and ARPES. Most of these results are complemented by DFT calculations, which enable us to estimate numerous parameters, such as film adhesion energies and the energies of a variety of 1D and 0D atomic-scale defects.

All Welcome

Biography

Martin Castell completed his PhD in Physics in 1994 at the University of Cambridge and then moved as a Junior Research Fellow to the Department of Materials at the University of Oxford. From 1999 he held a Royal Society University Research Fellowship, followed in 2005 by a University Lectureship, and was made a Professor in 2010. He has held visiting positions at the University of Toronto, Queen’s University Belfast, and the University of New South Wales. His main research activities involve the use of scanning tunneling microscopy and photoemission spectroscopy for the characterisation of oxide surface structures and molecular self-assembly on surfaces. He is currently also leading the development of a new type of ultra-sensitive gas sensor based on electrical percolation through conducting polymer networks. In 2016 he was awarded the John Yarwood Memorial Medal by the British Vacuum Council in recognition of his contributions to Surface Science.