XPS and AFM investigations of annealing induced surface modifications of MgO single crystals

yThe influence of annealing on surface composition and morphology of [1 0 0]-oriented MgO single crystals has been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The crystals were annealed at different temperatures between 700 and 1250 C in air for 12 h. XPS measurements show that the surface of a crystal, exposed to atmosphere for few days, consists of Mg(OH)(2) and MgCO3. Annealing at temperatures > 700degreesC is found to yield chemically pure MgO surfaces. AFM measurements show that surface morphology strongly depends on the annealing temperature. Atomically smooth surface, with step-and-terrace structure having terraces of similar to 700 nm wide and steps of 0.4 or 0.2 nm heights, is obtained on annealing at 1100degreesC. (C) 2002 Elsevier Science B.V. All fights reserved.