Surface properties of Hafnium diboride(0001) as determined by X-ray photoelectron spectroscopy and scanning tunneling microscopy

The surface structure and properties of the HfB2(0 0 0 1) (Hafnium diboride , HfB2) surface have been investigated with X-ray photoelectron spectroscop y, low energy electron diffraction (LEED), and scanning tunneling microscop y (STM). Annealing temperatures above 1900 degreesC produce a sharp (1 x 1) LEED pattern, which corresponds to STM images showing flat (0 0 0 1) terra ces with a very low contamination level separated by steps 3.4 Angstrom in height, correspending to the separation of adjacent Hf planes in the HfB2 b ulk structure. For lower annealing temperatures, extra p(2 x 2) spots were observed with LEED, which correspond to intermediate terraces of a p(2 x 1) missing row structure as observed with STM. (C) 2001 Elsevier Science B.V. All rights reserved.