Simultaneous angle-resolved measurement of the band structure of single-crystal graphite by an improved two-dimensional display analyzer

We have embodied a new version of two-dimensional display-type spherical mirror analyzer [H. Daimon and S. Ino, Rev. Sci. Instrum. 61, 57(1990)]. A couple of concentric hemispherical small grids and 12 pairs of obstacle rings have been attached to the original type of analyzer in order to operate with a constant pass-energy mode and improve the uniformity of the energy resolution of the analyzer all over the detection area, respectively. We performed a test on the resolution of the analyzer, and applied it to the simultaneous angle-resolved photoelectron spectroscopy on the band structures of single-crystal graphite (Kish graphite) within the acceptance cone of ±50°. The observed band structure is in good agreement with those reported by other investigators. We observed a ring-like pattern which enlarged as the binding energy approached the Fermi level. This ring is ascribed to the cross section of the π band. Although the designed energy resolution is 1% of the pass energy, the minimum value realized reached in this study was 0.2 eV for the pass energy of 10 eV [H. Daimon, Rev. Sci. Instrum. 59, 545 (1988); 61, 205 (1990)].