Univ Saarlandes Fachbereich Expt Phys D-66041 Saarbrucken Germany
Univ Michigan Randall Lab Phys Ann Arbor Mi 48109
Univ Calif Los Alamos Natl Lab Los Alamos Nm 87544
Ames Lab Ames Ia 50011
Iowa State Univ Sci & Technol Ames Ia 50011
Stanford Univ Dept Appl Phys Stanford Ca 94305
Max Planck Inst Festkorperforsch D-70569 Stuttgart Germany
Univ Kiel Inst Expt Phys D-24118 Kiel Germany
Univ Konstanz Fak Phys D-78434 Constance Germany

The electronic structure of the layered compound 1T-TiTe2 has been studied in detail by high-resolution angle-resolved photoelectron spectroscopy (ARPES) and density-functional band calculations. The results confirm the semimetallic nature of this material as due to an overlap of Te 5p- and Ti 3d-like conduction bands. We find an overall good correspondence between experiment and theory, with ail ARPES structures accounted for by the: calculated band structure. Particular focus is applied to the bands near the Fermi level and to the Fermi-surface topology. Interesting behavior is observed for an essentially Ti 3d(z)2-derived conduction band, whose measured Fermi vector and qualitative shape are excellently reproduced by the calculation. However, the experimental energy dispersion of the Ti 3d,2 ARPES peak appears to be considerably reduced with respect to band theory. From these results we obtain a picture of the electronic structure of 1T-TiTe2 as that of a Fermi liquid with renormalized quasiparticle dispersions and a Fermi surface in accordance with Luttinger's sumrule. We show that the experimental Ti 3 d(z)2 emission is quasi-two-dimensional near the Fermi surface, which, together with its being remarkably unobscured, virtually free of any interference with other spectral structures or inelastic background, makes it an ideal object for ARPES line-shape studies on a Fermi-liquid system.
 

Physical Review B, 54 2453-2465, 1996.