## 2009

**Schottky Barriers Seminar 2**

Andrew Vick, Surface Physics, University of York

February 6th, 11:30

Andrew continued his series of seminars on Schottky Barriers. In this talk he covered interpretation of experimental I-V curves and the relation of these to theoretical models. The discussion focussed upon the approximations that are made in order to contruct macroscopic theoretical models.

**An experimental surface density of states for holmium silicide**

Charles Woffinden, Surface Physics, University of York

Febraury 5th, 13:15

Using our in-house Metastable De-excitation Spectroscopy (MDS) apparatus Charles Woffinden and Andrew Pratt have recently carried out extensive measurements of the surface density of states of the 2D and 3D rare earth silicides on Si(111). In this talk Charles outlined the results and demonstrated the power of a deconvolution technique that is being applied to aid the analysis of the MDS data. The data were compared to local density of states simulated by C. Eames recently using DFT and the good agreement demonstrates the power of MDS in its extreme surface sensitivity. Useful discussion followed including suggestions on how to perform error analysis of deconvoluted data.

**The basic principles of TEM**

Jeremy Mitchell, Surface Physics, University of York

January 23rd, 11:15

The TEM is a powerful tool for obtaining information about a sample, the talk is an introduction to the very basics of the TEM and will include:

- The basic theory behind the various imaging modes of the TEM

- The sources of contrast that make up a TEM image

- The information about the sample that can be gained from each of the modes

- The strengths and weaknesses of the TEM for sample analysis

In the discussion the importance of simple ray diagrams in establishing the basic principles of the TEM was emphasised.

**Schottky Barriers Seminar 1**

Andrew Vick, Surface Physics, University of York

January 15th, 11:30

In his PhD project Andrew is attempting to measure local Schottky Barrier heights using an STM tip. In this seminar he gave a general overview of Schottky Barrier physics and introduced us to his project. The discussion focussed on which material we would like to cover in future Schottky Barriers seminars, namely what is the current state of measurement and simulation in the literature.