Assistant Professor
Physical Chemistry, Theoretical Chemistry
Chemistry and Physics of Surfaces
Ph. D. Cornell University 1991
Voice:
(207) 581-1171 (279 Aubert Hall)
(207) 581-2268 (137 Sawyer Research Center)
Email: brian.frederick@umit.maine.edu
My research has integrated a broad range of techniques to provide geometric, electronic and vibrational structure with kinetic information to understand relatively complex systems from an atomic and molecular point of view. I have been primarily interested in oxide surface chemistry and in molecular adsorption and ordering processes, and organic film growth at metal single crystal surfaces. The group is also involved in development and application of statistical methods for data analysis and instrument development for electron spectroscopy. An important component is the use of theoretical methods, such as ab initio electronic structure calculations (HF,DFT) to complement and interpret experimental data, including occupied and virtual orbitals, potential energy surfaces for internal degrees of freedom, and vibrational frequencies.
Specifically, the group uses electron-based techniques for diffraction (low energy electron diffraction, (LEED)), vibrational spectroscopy (high resolution electron energy loss spectroscopy, HREELS), electronic structure (X-ray or UV photoelectron spectroscopy, (XPS, UPS)), and kinetics (thermal desorption spectroscopy, TDS). We are interested as well in photon-based techniques, making extensive use of reflection absorption infrared spectroscopy (RAIRS, FTIR, IRAS), and have demonstrated the possibility of using reflectance anisotropy (RA), also known as differential reflectance, for following molecular adsorption and ordering at metal surfaces.
Current activity in the group centers around two areas:
1) development of state-of-the-art methods for "Inelastic Diffraction", combining the high energy resolution of HREELS (~2 meV, 16 cm-1), for measuring vibrational excitation in electron beam scattering, with high momentum resolution in spot profile analysis LEED optics.
2) investigation of the physical chemical aspects of oxide gas sensors, including the role of adsorption, desorption kinetics, defect reactions, diffusion processes and the mechanisms by which these processes control conductivity in thin films and single crystals.
Selected publications:
B. G. Frederick, J. R. Power, R. J. Cole, C. C. Perry, Q. Chen, S. Haq, Th. Bertrams, N. V. Richardson and P. Weightman, "Adsorbate azimuthal orientation from reflectance anisotropy" Phys. Rev. Lett. 80 (1998) 4490.
B. G. Frederick, A. W. Munz, Th. Bertrams, Q. Chen, C. C. Perry and N. V. Richardson, "Negative Ion Mediated Molecular Manipulation with STM of c(8x2) benzoate/Cu(110)", Chem. Phys. Lett., 272 (1997) 438-444.
B. G. Frederick, Q. Chen, F. M. Leibsle, M. B. Lee, K. Kitching and N. V. Richardson, "Long range periodicitiy in c(8x2) benzoate/Cu(110) surface: A combined STM, LEED and HREELS Study", Surf. Sci., 394 (1997) 1-25.
B. G. Frederick, F. M. Leibsle, S. Haq and N. V. Richardson, "Evolution of lateral order and molecular re-orientation in the benzoate/Cu{110} system", Surf. Rev. Lett., 3 (1996) 1523-1546.
B. G. Frederick, M. B. Lee, and N. V. Richardson, "A vibrational characterisation of the O/Al(111) system: a reassignment of HREELS data", Surf. Sci. 348 (1996) L71 L74
B. G. Frederick, Q. Chen, S. M. Barlow, N. G. Condon, F. M. Leibsle, and N. V. Richardson, "Orientation and periodicity in the c(4x8) and p(2x1) structures of 3 Thiophene Carboxylic Acid on Cu(110)", Surf. Sci., 352-354 (1996) 238-247.
B. G. Frederick, G. L. Nyberg and N. V. Richardson, "Spectral restoration in HREELS", Proc. 7th Int. Conf. Vibrations at Surfaces, Italy, June 1993, J. Electron Spectrosc. Rel. Phenom. 64/65 (1993) 825-835.
B. G. Frederick, G. Apai and T. N. Rhodin, "Surface phonons in thin aluminium oxide films; thickness, beam energy, and symmetry mixing effects", Phys. Rev. B 44 (1991) 1880-1891.