Angle resolved photoemission on K{sub 0.3}MoO{sub 3}, TiTe{sub 2} and Ti{sub 1+x}S{sub 2}

Abstract

The authors have performed high resolution angle resolved photoemission spectroscopy (HRARPES) on samples of K{sub 0.3}MoO{sub 3}, TiTe{sub 2} and Ti{sub 1+x}S{sub 2}, materials which are a quasi-one dimensional metal, a quasi-two dimensional metal, and a quasi two-dimensional metal (x > 0) or semi-conductor (x = 0), respectively. They are interested in looking at these samples using HRARPES as part of the general program to assess the use of photoemission to determine whether a particular system behaves like a Fermi liquid or not. For one dimensional metallic systems, angle integrated photoemission studies to date, e.g., reveal that, contrary to higher dimensional cases where a sharp Fermi cutoff is seen at the Fermi level, there is very little weight at the Fermi level. It seems that there is yet no agreement why this is so. They think that detailed information they get from HRARPES will help them answer this question. The system Ti{sub 1+x}S{sub 2} gives the possibility to control the filling of the Ti 3d conduction band by adjusting x. Interest in this system lies in measuring the spectra and the line shape of samples with different stoichiometry and correlating the spectroscopic data with the corresponding transport data.