NATURE OF MULTILAYER STEPS ON THE (100)CLEAVAGE PLANES OF MGO SINGLE-CRYSTALS

The results of an AFM study of the nature of multilayer steps on the [ 100] cleavage faces of MgO crystals is described and discussed. The re sults show that (i) multilayer cleavage steps of a width between 55 an d 590 nm and of a slope between about 1 and 8 are stable. (ii) the ter minal planes of multilayer steps are composed of high-index vicinal fa ces with indices (701). (4201) and (7701) for the [010] steps with res pect to the (100) cleavage. which do not correspond to the low-index p lanes of the equilibrium form of MgO crystals, and (iii) that the curv ed parts of the profile of a multilayer cleavage step in its upper and lower regions extend to a distance equal to the width of the step. (C ) 1997 Elsevier Science B.V.