Magnetism in the few-monolayers limit: A surface magneto-optic Kerr-effect study of the magnetic behavior of ultrathin films of Co, Ni, and Co-Ni alloys on Cu(100) and Cu(111)

Proximity effects on dimensionality and magnetic ordering in Pd/Fe/Pd trialyers

“…These changes can be captured by fitting the results using the relation M (H = 0.2 mT, T ) ∝ −t β eff , where t = T /T C − 1. When using a field, albeit small, the signal in the immediate vicinity of the transition temperature is affected 3 . The fits to the magnetization were therefore performed over the temperature range 0.5 T C to 0.98 T C , capturing the changes in the magnetization of different elemental sites and allowing a direct comparison to the established effective exponents.…”

“…The relative contribution of the interfaces can be altered through the choice of the layer thickness which allows the Curie temperature to be selected from anywhere between zero and the bulk ordering temperature. 3,4 It is not only the ordering temperature that changes with layer thickness. A transition from 3D to 2D-like behavior is observed as the layer thickness is reduced below a critical value (d c ), which in turn depends both on the choice of material and its crystalline orientation [5][6][7] .…”

“…β eff ∼ β). [5][6][7]9 However, when the magnetic interactions are not uniform the scaling laws become inappropriate for determining the spatial or spin dimensionality and β eff can take non-universal values which will depend on both the layer thickness as well as other local boundary effects 8 .…”

Magnetic properties of thin Ni films measured by a dc SQUID-based magnetic microscope

“…5 ͑B͒ Devices which provide high-resolution imaging of magnetic structures such as a magnetic force microscope, and magneto-optic Kerr effect device. [6][7][8] ͑C͒ Synchrotron source photon beams techniques. The microscopic magnetism can be studied by this method 9,10 and resonant photon scattering can be used in connection with studies of the surface magnetism.…”

“…14,15 It has been observed that the orientation of magnetization in epitaxial Ni films depends on the film thickness. 7,18 For thicknesses less than 7 layers the magnetization is in-plane, while the easy direction is out of plane for thicker films. It has been demonstrated that such types of systems can exhibit a perpendicular magnetization in a wide range of thicknesses ͓10-60 Å of Ni for vacuum /Ni/Cu/Si͑001͒ and 20-135 Å of Ni for Cu/Ni/Cu/Si͑001͔͒.…”