Atomic force microscopy and scanning electron microscopy study of MgO(110)surface faceting

Phosphoric- and nitric-acid etching of the MgO(110) surface generates vicin al faceting in both the < 001 > and < 110 > directions. Vacuum annealing (t o 1000 degrees C) does not introduce thermal faceting, and does not alter t he chemical-etch morphology. Three types of acid-induced faceting (early-st age pits, later-stage grooves, and inverted trapezoidal pyramids) are seen as a function of etching time. Facet-angle analysis by atomic force microsc opy (AFM) and scanning electron microscopy (SEM) shows the etch morphology to be vicinal, with angles in the range of 9 degrees to 23 degrees, not the low-energy {100} planes expected from minimization of surface energy. (C) 2000 Elsevier Science B.V. All rights reserved.