Molecular Physics seminar

Surface resonance states on Pd(110) / X-­‐ray micro tomography -­‐ A case study of LiFePO4 samples

by Peter Amann (Chemical Physics Department)

FD 41 ()

FD 41

In this talk I will give a survey of what I did before I came to the University of Stockholm. The talk will be split into two parts. In part i.) I will focus on the surface of clean and hydrogen-covered Pd(110), which was investigated by angle-resolved photoemission spectroscopy. For both surfaces, a lowdimensional Tamm-type surface resonance is found around the Fermi-energy (EF) at S-bar. Interestingly, upon 1.5 ML Hydrogen adsorption the pairing-row reconstruction on Pd(110) develops together with a satellite peak of the S-bar resonance. The band dispersion of this satellite is parallel to the dispersion of the main resonance, but shifted to lower energies by roughly 400meV at 100K. The results put the question up if this is related to a paramagneticferromagnetic transition. Bulk Pd is known to be nearly ferromagnetic. Surface-states or resonances are very sensitive to the local magnetic order at the surface and act as a surface localized magnetometer. In part ii.) I will present the method of X-ray micro tomography and discuss LiFePO4 electrode materials in more detail. By combining LiFePO4 with 3D embroidered technologies, higher energy- and power densities are expected. X-ray micro tomography is used to study the 3D geometry, verify the production process and to deliver the basis for numerical simulations.