Spin dynamics and magnetotransport in ultra-low damping Co100-xFex layers

Place: conference room, IMDEA Nanociencia.

Abstract:

The manipulation of the electron charge and the spin for the development of more efficient spintronic devices has been a topic of increasing interest in recent years. In particular, systems based on metallic ferromagnets with very low damping, a parameter that determines the speed and energy consumption during the operation of modern electronic devices, are excellent candidates for spin current injection. Recently, it has been reported that the Co25Fe75 alloy exhibits low magnetic damping, due to the features of the band structure in Co100-xFex alloys. In this talk I will discuss the magnetotransport and spin dynamics in Co100-xFex/HM (HM= Pt, Ta) bilayer systems, grown on MgO (100) single crystal substrates. Characterization by Kerr magnetometry, transmission electron microscopy, magnetotransport and ferromagnetic resonance allowed to determine that the Co100-xFex films grow epitaxially with a cubic structure rotated 45° with respect to the (100) direction of the MgO substrate plane, determining the magnetization easy axis. We also investigate the angular dependence of the anisotropic magnetoresistance (AMR) of the epitaxial Co100-xFex films with the applied current parallel and perpendicular to the easy and hard magnetization axes to discuss the magnetization process and to evaluate the tunability of the AMR. Finally, first results on spin transport characterization using spin torque ferromagnetic resonance allowed the detection of induced voltages associated to the conversion of charge current to spin current, demonstrating efficient conversion in Pt layers.

Short bio

Luis Avilés Félix is a researcher of the National Council for Scientific and Technical Research (CONICET) from Argentina. He develops his research activities at the Department of Magnetism and Magnetic Materials in the Physics Deparment of the Centro Atómico Bariloche. Luis received his degree in Physics in 2010 from the Science’s Faculty of National University of Engineering in Lima, Perú. In 2011 he moved to Argentina and obtained his Ph.D. in Physics in 2015 from Instituto Balseiro/Cuyo’s National University with a fellowship sponsored by CONICET/Argentina. Luis first postdoc at the Magnetic Resonance Laboratory of Centro Atómico Bariloche in Argentina between 2016-2018 consisted on the generation and detection of spin currents with synthetic antiferromagnets. A second postdoc at SPINTEC laboratory from Commissariat à l’énergie atomique et aux énergies alternatives (CEA) in Grenoble, France (20182020) was focused on the development of optically-switchable synthetic ferrimagnetic materials and its integration within MTJ structures. Dr. Avilés current research activities involves the study of spin dynamics in low dimensional systems and magnetotransport in micro and nanostructures.