An effective method to probe local magnetostatic properties in a nanometric FePd antidot array

• Grant number: 11/02207-6
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: March 01, 2011
• End date: August 31, 2011
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Marcelo Knobel
• Grantee: Marcelo Knobel
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 06/60440-0 - Study of strongly correlated systems in extreme conditions, AP.TEM

Abstract

A simple method to quantitatively characterize the local magnetic behaviour of a patterned nanostructure, like a ferromagnetic thin film of antidot arrays, is proposed. The first-order reversal curve (FORC) analysis, coupled with simulations using physically meaningful hysterons, allows us to obtain a quantitative and physically related description of the interaction field and each magnetization reversal process. The hysterons system is built from previously known hypotheses on the magnetic behaviour of the sample. This method was successfully applied to a highly hexagonal ordered FePd antidot array with nanometric dimensions. We achieved a complete characterization of the two different magnetization reversal mechanisms in function of the in-plane applied field angle. For a narrow range of high fields, the magnetization initiatesrotating reversibly around the pores, while at lower fields, domain walls are nucleated and propagated. This in-plane magnetization reversal mechanism, partly reversible and partly irreversible, is the only angularly dependent one.While going away from the easy axis, its reversible proportion increases, as well as its switching field distribution. Finally, the results indicate that the high surface roughness between adjacent holes of the antidot thin film induces a parallel interaction field. The proposed method demonstrates its ability also to be applied to characterizing patterned nanostructures with rather complex magnetizationreversal processes. (AU)