Surface structure analysis of Zr-O/W(100) at high temperature by x-ray photoelectron diffraction

Temperature dependence of the surface structure of Zr-O/W(100) was obtained by low-energy electron diffraction observation to check the phase transition of the surface. After flashing the Zr-O/W(100) to 1500 K, the c(2 x 4) + c(4 x 2) double-domain structure was clearly observed at room temperature. This surface changed to the p(1 x 1) phase over 1300 K, accompanied by a decrease in the work function. The temperature dependence of the work function was obtained from the shift of the energy distributions of secondary electrons. The reversible phase transition of the Zr-O/W(100) surface and the decrease in the work function of 2 eV at high temperature were checked. X-ray photoelectron diffraction (XPD) measurements at 1500 K have been performed to investigate the surface structure at the working temperature of the Zr-O/W(100) electron emitter. The O1s XPED pattern included some patterns that can be regarded as the influence of Zr-O complexes on the W(100) surface. Copyright (C) 2005 John Wiley Sons, Ltd.