Magnetic Domain Wall Ferromagnetic Resonance Confirmed by Magnetotransport Measurements and Kerr Microscopy

Abstract

SYMPOSIUM 17. POSTERS Magnetic Domain Wall Ferromagnetic Resonance Confirmed By Magnetotransport Measurements And Kerr Microscopy Laura Fernández-García1*, Sandra Ruiz Gómez2, Rubén Guerrero3, José Luis Prieto4, Claudio Aroca4, Manuel Muñoz1 1 Consejo Superior de Investigaciones Científicas - Instituto de Tecnologías Físicas y de la Información (CSIC – ITEFI), Serrano Str. 144, Madrid, Spain 2 Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden, Germany 3Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Faraday Str. 9, Madrid, Spain 4 Instituto de Sistemas Optoelectrónicos y Microtecnología - Universidad Politécnica de Madrid (ISOM-UPM), Ciudad Universitaria, Madrid, Spain manuel.munoz@csic.es In spintronic applications, the generation and manipulation of magnetic domain walls have been an important research field since its proposal as the key element in magnetic data storage structures [1]. Nowadays, these systems are studied, not only for their information storage capabilities, but for its potential application to process such information at a small computational cost [2, 3], and for their ability to generate microwave signals [4]. In this work we study the ferromagnetic resonance of a permalloy nanostrip with a gold microantenna sputtered on top, measured by the stripline ferromagnetic resonance tehcnique [5]. The behavior of the microstrip resonance with the radiofrequency stimulus and the applied magnetic field fits the Kittel's equation. Additionally, a new resonance is observed between 4 Oe and 9 Oe for an applied radiofrequency signal between 2.0 GHz to 3.0 GHz. Throughout magnetoresistance measurements, this new resonance at low magnetic fields was found to correspond to the formation and pinning of a magnetic domain wall. The presence of the domain wall was confirmed by Kerr microscopy. Our results show a distinctive RF emission caused by the DW whose frequency increases linearly with the external field, which can be very important for applications in computing and communications.