ITINERANT MAGNETISM IN ULTRATHIN METALLIC FILMS

✍ Scribed by ROY F WILLIS

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 1021 KB
• Volume: 54
• Category: Article
• ISSN: 0079-6816
• DOI: 10.1016/s0079-6816(97)00009-9

✦ Synopsis

This paper addressesthe question: "How do we define a two-dimensional itinerantmagnet?" Resultsare presentedindicatinga cross-overfrom threedimensional (3D) to two-dimensional(2D) behavior at a finite-size fihn thickness. It is arguedthat quantizationof the electronicstates in ultrathin metallic films dictate this behavior. Data from a broad range of epitaxial ferromagneticfihns grownon differentmetallicsubstratessuggesta cross-over into just two classesof 2D behavior, viz 2D Ising model in the presence of uniaxial surface anisotropyand finite-sizelattice 2D XY model behavior in films in which the preferreddirectionof magnetizationlies in-plane. In this ultrathin film 2D limit, the Curie temperaturefalls rapidly to zero as the thicknessapproachesa singlemonolayerdue to the suddenonsetof disordered microdomains.