Low energy photoelectron diffraction analysis at high angular resolution of Cu and Mn/Cu surfaces

X-ray photoelectron diffraction simulations using a real-space approach are shown to accurately produce the extraordinarily detailed photoelectron diffraction pattern from Cu{111} at an electron kinetic energy of 523.5 eV. These same simulations show that most sensitivity is obtained when using low energy electrons at high angular resolution. Structural differences are observed to be greatest around a kinetic energy of $∼100eV$ and many of the features observed in the photoelectron diffraction patterns may be directly related to phenomena observed in low energy electron diffraction patterns from the same surface. For Cu{100}, simulations of buckled surfaces with a Mn overlayer predict that low energy photoelectron diffraction can easily discriminate chemical and structural differences. Even the effects of the relaxed surface of Cu{100} is indeed observable along azimuthal scans around a kinetic energy of 100 eV. Our results show that low energy photoelectron diffraction is extremely sensitive to changes in surface structure if high resolution patterns are acquired.