Growth and magnetism of self-organized CoxPt1−x nanostructures on Au(1 1 1)

• Published in: Journal of physics. D, Applied physics Vol. 47; no. 7
• Main Authors: Moreau, N, Repain, V, Chacon, C, Girard, Y, Lagoute, J, Klein, J, Rousset, S, Scheurer, F, Ohresser, P
• Format: Journal Article
• Language: English
• Published: IOP Publishing 19.02.2014
• Subjects: CoPt; nanostructures; Physics; surface; XMCD; CoPt; surface; nanostructures; XMCD
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/47/7/075306

The structural and magnetic properties of self-organized CoxPt1−x nanostructures grown by codeposition at room temperature on Au(1 1 1) are reported. The samples have been imaged by scanning tunnelling microscopy and characterized by x-ray magnetic circular dichroism in the same ultra-high vacuum setup. We observe that the ordered growth is preserved for a large range of Pt concentrations. The magnetization cycles as functions of the magnetic field angle and the temperature are well reproduced by a simple model, giving a good estimation of the magnetic anisotropy distributions in these assemblies of nanostructures. The initially out-of-plane anisotropy for pure Co nanostructures strongly decreases until it lies in-plane for a 40% Pt concentration. This spin reorientation transition and the measured broadening of the switching field distribution with x are discussed using a phenomenological pair model that reproduces well the main magnetic properties of CoxPt1−x epitaxial nanostructures.