The surface composition and structure of the Pd(001)-(2 x 2)p4g-Al phase were studied by low-energy ion scattering and low-energy electron diffraction. It was found that annealing Al-covered surfaces with initial coverages from half to more than 1ML to about 900K gave rise to a stable (2 x 2)p4g low-energy electron diffraction pattern. The ion-scattering data suggested that the reconstruction was due to an ordered c(2 x 2)Al-Pd underlayer below a clock-rotated (001) Pd termination.

The Role of Interfacial Strain in the Surface p4g Reconstruction - a Comparison between Pd(001)-(2 x 2)p4g-Al and Cu3Pt(001). Y.G.Shen, D.J.O'Connor, R.J.MacDonald: Journal of Physics - Condensed Matter, 1997, 9[40], 8345-58