X-RAY PHOTOELECTRON SPECTROSCOPIC STUDIES ON CERAMIC COMPOSITES CONTAINING YTTRIA-STABILIZED ZIRCONIA AND ALUMINA

X-ray photoelectron spectroscopy has been used to characterize the sur faces of ceramic composites containing yttria-stabilized zirconia and alpha-alumina. One of the surfaces of the composite was modified by ma gnesia diffusion for improved wear resistance. Formation of a magnesia -alumina spinel was detected at the modified surface. Significant shif ts in the binding energy of Al 2p and O 1s core levels were observed f or the modified and the unmodified surface. These were compared with t he core levels of standard spinel and sapphire. Auger parameters for s everal elements were measured for the modified and the unmodified surf ace as well as the standards. These parameters provided useful informa tion regarding cation-anion coordination in the oxides and assisted in identifying an impurity phase. Valence-band spectra were obtained fro m the various surfaces under study. These spectra were utilized in a s emiquantitative way to characterize the different phases present on th e surface of the composite.