545 research outputs found
Epitaxial thin films oxides on Fe: what happens when a low dimensional oxide grows on a highly reactive metal substrate?
No full textThe investigation of oxide films with a thickness of a few nanometers or below grown on another substrate is a scientific topic that has recently attracted a huge amount of experimental and theoretical research work [1].
In this contribution we shall focus on some of the recent advances in understanding the formation of transition metal oxide/Fe interfaces [2,3]. Fe can be considered on the one hand as a prototypical example of ferromagnetic material, and on the other hand as an example of a highly reactive metal. The former characteristic makes it particularly appealing for spintronic applications and magnetic storage media, while the latter makes the preparation of well-defined oxide/metal interfaces a difficult task. For this reason, despite the large body of literature focusing on the preparation and characterization of ultra-thin oxide films on inert materials such as noble and quasi noble metals, comparatively little is known about the atomic scale mechanisms driving the formation of the transition metal oxide/Fe interfaces.
In the first part of the talk we shall discuss the stabilization of single-layer-thick oxide films on Fe, by using selected examples involving the deposition of transition metals on the well-ordered and defect-free Fe(001)-p(1 × 1)O surface. This is characterized by one oxygen atom per surface unit cell which can be used as a reservoir for the stabilization and investigation of Fe-supported twodimensional transition metal oxides [4,5], avoiding at the same time the Fe oxidation occurring when more traditional preparation procedures (such as for instance metal deposition in a reactive oxygen atmosphere) are employed.
In the second part we shall discuss the growth of oxide films out of the interfacial layer, with particular emphasis on the growth mode leading at the same time to sharp interfaces, useful to correctly modeling the interfacial physical phenomena, and atomically flat surfaces, crucial to allow scanning probe microscopy studies down to the atomic scale.
References: [1] See e.g. S.Valeri and G. Pacchioni, eds., Oxide Ultrathin Films (Wiley-VCH Verlag, Weinheim,2011).
[2] M. Finazzi, L. Duò, and F. Ciccacci, Surf. Sci. Rep. 64, 139 (2009).
[3] M. Finazzi, L. Duò, and F. Ciccacci, eds., Magnetic Properties of Antiferromagnetic Oxide Materials: Surfaces, Interfaces and Thin Films (Wiley-VCH Verlag, Weinheim, 2010).
[4] A. Picone, G. Bussetti, M. Riva, A. Calloni, A. Brambilla, L. Duò, F. Ciccacci, and M. Finazzi, Phys. Rev. B 86, 075465 (2012).
[5] A. Picone, G. Fratesi, M. Riva, G. Bussetti, A. Calloni, A. Brambilla, M.I. Trioni, L. Duò, F. Ciccacci, M. Finazzi, Phys. Rev. B 87 (2013) 085403
Origin of the Laplace Force Applied to a Current-Carrying Wire Immersed in a Magnetic Field
Get PDFThe macroscopic force (called the Laplace force) acting on a wire carrying an electric current placed in a magnetic field is a consequence of the Lorentz force acting on each charge inside the wire. Typically, the Laplace force is explained as a magnetic force resulting from the interaction of the moving charges with the external magnetic field. Such an interpretation, however, is too simplistic and does not take into account all the interactions between the various charge populations inside the wire. This leads to a series of paradoxes that might hinder the understanding of this subject. For instance, a magnetic force cannot do any work, while a current-carrying wire in a magnetic field represents the paradigm to understand the working principle of an electric motor. Here, we will solve this and other inconsistencies by showing, with simple arguments comprehensible to undergraduate students, that the Laplace force is instead an electrostatic force
Plasmon-photon interaction in metal nanoparticles: Second-quantization perturbative approach
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Recent developments in linear and nonlinear near-field microscopy on single plasmonic nanoparticles
No full textRecent developments in linear and nonlinear near-field microscopy on single plasmonic nanoparticle
Magnetic Properties of Antiferromagnetic Oxide Materials
No full textMagnetic Properties of Antiferromagnetic Oxide Material
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