Magnetization Reversal in Arrays of Perpendicularly Magnetized Ultrathin Dots Coupled by Dipolar Interaction

T. Aign; P. Meyer; S. Lemerle; J. P. Jamet; J. Ferré; V. Mathet; C. Chappert; J. Gierak; C. Vieu; F. Rousseaux; H. Launois; H. Bernas

doi:10.1103/PhysRevLett.81.5656

Magnetization Reversal in Arrays of Perpendicularly Magnetized Ultrathin Dots Coupled by Dipolar Interaction

T. Aign, P. Meyer, S. Lemerle, J. P. Jamet, J. Ferré, V. Mathet, C. Chappert, J. Gierak, C. Vieu, F. Rousseaux, H. Launois, and H. Bernas

Phys. Rev. Lett. 81, 5656 – Published 21 December 1998

Abstract

Arrays of micron size perpendicularly magnetized ultrathin Co dots with 20 nm separation were obtained using ion irradiation by a focused ion beam and studied by polar magneto-optical microscopy. Because irradiation induces easy nucleation regions along dot borders, magnetization reversal inside the dots under a perpendicular field is due only to domain wall propagation, driven by applied field and dipolar interactions. Frustrated checkerboard patterns are observed in the demagnetized state, in agreement with numerical simulations. This opens the way to experimental studies on model arrays of interacting Ising dots.

Received 29 July 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.5656

Authors & Affiliations

T. Aign^1,*, P. Meyer¹, S. Lemerle¹, J. P. Jamet¹, J. Ferré¹, V. Mathet², C. Chappert², J. Gierak³, C. Vieu³, F. Rousseaux³, H. Launois³, and H. Bernas⁴

¹Laboratoire de Physique des Solides, URA CNRS 002, Université Paris-Sud, 91405 Orsay, France
²Institut d'Electronique Fondamentale, URA CNRS 022, Université Paris-Sud, 91405 Orsay, France
³Laboratoire de Microstructures et de Microélectronique, UPR CNRS 020, 196 Avenue Henry Ravera, BP107, 92225 Bagneux, France
⁴Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, UPR CNRS 6412, Université Paris-Sud, 91405 Orsay, France