Temperature dependence of x-ray photoelectron diffraction from copper: Surface and bulk effects

The temperature dependence of x-ray photoelectron diffraction (XPD) effects in azimuthal distributions of Cu 2$p_{3/2}$ and Cu 3p core-level intensities from a clean copper (001) surface has been measured in the range from 298 to 1010 K and for two polar angles of emission relative to the surface of theta=7° (highly surface sensitive) and theta=45° (more bulk sensitive). Measurements have been performed with typical angular resolutions of ∼±4°–6°, although some data obtained with a much higher resolution of ∼±0.6° are also discussed. Very-high-angular-resolution azimuthal scans of Cu 2$p_{3/2}$ intensity for theta values near 45° show much more fine structure and sensitivity to polar-angle variation than analogous results obtained at lower angular resolution.