Secondary Electron Yield and AES Measurements on Oxides, Carbide and Nitride of Niobium*

-. Secondary electron yield measurements before and after Ar ion sputter cleaning were made on Nb and Nb compounds of interest for rf superconducting cavities. Total secondary electron yields (a) for primary energies 20-1500 eV were measured for solid Nb (a max = 1.3 at 300 eV), anodized NbzOs (a max = 1.2 at 300 eV) and powders of: Nb(a max = 1.0 at 400 eV), NbO (a max = 0.9 at 400 eV), NbOz (a max = 1.0 at 400ev), NbzOs (a max = 0.95 at 400 eV), NbC( 0 max = 0.8 at 400 eV) and NbN (a max = 0.8 at 500 eV). Determinations were made for Auger elemental sensitivities, and the relationship between Auger peak heights and oxide stoichiometry is discussed. The sputter etch rate of anodized NbzOs was measured by depth profiling anodic coatings of known thickness.