Deconvolution of the Co3O4(110) Fuchs–Kliewer phonon spectrum

E. M. Marsh, S. C. Petitto, G. S. Harbison, K. W. Wulser, M. A. Langell
2005 Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films  
The Fuchs-Kliewer phonon spectrum of single crystal Co 3 O 4 ͑110͒ has been treated with a Fourier transform log deconvolution method, which removes multiple scattering features from the single loss spectrum. Auger electron spectroscopy ͑AES͒, x-ray photoelectron spectroscopy ͑XPS͒ and low-energy electron diffraction ͑LEED͒ were first used to characterize the Co 3 O 4 crystal establishing the cleanliness, composition, and order of the ͑110͒ surface. High resolution electron energy loss
more » ... opy ͑HREELS͒ was then used to obtain the phonon spectrum for an incident electron energy of 3.77 eV. Due to the strong dipole cross section for the Fuchs-Kliewer phonon modes, intense multiple electron scattering was detected, which provided a complicated and overlapping combination of all possible loss modes. Deconvolution removed the multiple loss modes to produce well-resolved Fuchs-Kliewer fundamental phonon losses at 218, 373, 598, and 682 cm −1 ͑27.0, 46.2, 74.1, and 84.6 meV͒. These values are compared to the fundamental loss energies obtained by resolving the overlapping peak structure with standard peak fitting procedures, which confirmed the single loss energies obtained with the deconvolution procedure. Deconvolution results from the four fundamental phonon spectrum of single crystal Co 3 O 4 ͑110͒ were also compared to those from the simpler spectra of CoO͑100͒ and thin-film CoO͑100͒-Co 3 O 4 epitaxy and some practical aspects of the deconvolution process discussed in this context.
doi:10.1116/1.1863972 fatcat:i2rlajs7gbdtropg54kfizbe44