Stress and magnetic properties of surfaces and ultrathin films

Stress measurements with sub-monolayer sensitivity are performed to investi gate the correlation between mechanical film stress and magneto-elastic ani sotropy in epitaxial ferromagnetic monolayers. The magneto-elastic coupling B-1 of Fe(1 0 0) films is measured directly. Magnitude and sign of B-1 dev iate from the respective bulk value. A strain-dependent correction of the m agneto-elastic coupling coefficient B-1 describes the apparent thickness de pendence of B-1 for film thicker than 10 nm. For thinner films, the possibl e contribution of surface corrections is discussed to explain the almost co nstant B-1. The implications of a modified magneto-elastic coupling for the anisotropy of ultrathin films is elucidated. (C) 1999 Elsevier Science B.V . All rights reserved.