LEEM investigations of ion beam effects on clean metal surfaces: quantitative studies of thedriven steady state

Abstract

The technique of low-energy electron microscopy (LEEM) pioneered by Bauer has beenadapted here to the investigation of ion beam processes on crystal surfaces by theincorporation of an intense and tunable source of selectable, energetic ions into a LEEMdesigned by Tromp et al. In this paper we explain principles that constrain the design ofthis tandem instrument, to permit observation of surfaces during irradiation. We alsodescribe experiments that probe the driven steady state of surfaces subject to theperturbation of a uniform and constant flux of self-ions. The emphasis is on the example ofPt− ions irradiating the Pt(111) surface. We explore a regime of linear response at elevatedtemperature in which the driven nucleation and universal driven growth of surface islands,and the driven cycling of Bardeen–Herring sources and other surface clocks, may beunderstood in a fully quantitative manner.