Enhanced magnetocrystalline anisotropy in an ultra-dense array of air-exposed crystalline cobalt nanowires

Themagnetic anisotropy of an ultradense array of crystallinecobaltnanowires is investigated by means of broadbandferromagnetic resonance and magnetictorque measurements. The array isgrown epitaxially in solution on a Pt(111) film and consists of single crystalline metallicwires with a diameter of 6.2  nm and a center-to-center interwire distance of 9.6 nm. The shapeanisotropy and the Co hexagonal compact structure with the c-axis along thewire axis combine with each other to impose a perpendicularmagnetic anisotropy despite the high density of 8  × 1012 wires/in.2. The intrinsic uniaxialmagnetocrystallineanisotropy constantsK1 andK2 are extracted from theferromagnetic resonance andtorque measurements using a mean field approach accounting for the interwire dipolar interactions. At room temperature, and despite air exposure, an unexpected increase ofK1 andK2 of more than 40% with respect to the bulk is evidenced.

Source: Applied Physics Letters - November 17, 2016 Category: Physics Authors: I. S. Camara, C. Achkar, N. Liakakos, A. Pierrot, V. Pierron-Bohnes, Y. Henry, K. Soulantica, M. Respaud, T. Blon and M. Bailleul Source Type: research