IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Effective demagnetizing tensors in arrays of magnetic nanopillars
Autor/es:
PRIDA, V.M.; PIROTA, K.R.; MENDOZA ZÉLIS, P.; COSTA-ARZUZA, L.C.; LÓPEZ-RUIZ, R.; VEGA, V.; BÉRON, F.; SÁNCHEZ, F.H.
Revista:
PHYSICAL REVIEW B
Editorial:
APS Physics
Referencias:
Lugar: Washington; Año: 2017 vol. 96
ISSN:
1098-0121
Resumen:
A model describing the effect of magnetic dipolar interactions on the susceptibility of magnetic nanopillars is presented. It is an extension of a recently reported model for three-dimensional randomlike dispersions of nearlyspherical nanoparticles in equilibrium [Sánchez et al., Phys. Rev. B 95, 134421 (2017)], to well-ordered arrays of nanoparticles out of equilibrium. To test it, a high-quality benchmark consisting of a two-dimensional hexagonal arrangement of quasi-identical parallel nickel nanopillars embedded in a porous alumina template was fabricated. This model is based on an effective demagnetizing tensor, which only depends on a few morphological parameters of the sample, as the nearest-neighbor distance between pillars and the volume fraction of pillars in the specimen. It allows us to obtain the nanopillar intrinsic susceptibility tensor from the magnetic response of the nanopillar ensemble. The values of the in-plane and normal-to-plane susceptibility of the sample are successfully predictedby the model. Furthermore, the model reproduces the susceptibility in the applied field direction, measured fordifferent applied field angles. In this way, it provides a simple and accurate treatment to account for the complexmagnetic effects produced by dipolar interactions.