Micromagnetic Modeling of All-Optical Switching

[EN] The control of the magnetization at the microscale by pure optical means is fundamentally interesting and promises faster speeds for data storage devices. Although several experiments have shown that it is possible to locally reverse the magnetization of a ferromagnetic system by means of laser pulses, a completely theoretical description of these All Optical Switching processes is still lacking. Here, we develop an advanced micromagnetic solver that is applied to the numerical study of the All Optical Switching. The solver is based on the Landau-Lifshitz-Bloch equation that governs the dynamics of the magnetization coupled the microscopic three temperatures model, which describes the temporal evolution of the temperatures of the subsystems as caused by laser heating. The helicity-dependent magnetization switching is evaluated by a magneto-optical effective field caused by the Inverse Faraday Effect when a circularly polarized laser is applied to the sample. All the other usual terms of a full micromagnetic model are included (exchange, anisotropy, DMI…). As a test, the model is used to describe the local magnetization switching of thin film samples with high perpendicular anisotropy. The results are in good agreement with available experimental observations.MAT2014- 52477-C5-4-P, MAT2017-87072-C4-1-P, and MAT2017-90771-REDT from the Spanish government SA090U16 and SA299P18 from the Junta de Castilla y Leon

Virtualización para el desarrollo de experiencias de electromagnetismo

Memoria ID-094 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021

Elaboración de nuevos recursos docentes para el estudio de la física del estado sólido

Memoria ID-0153. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018

Elaboración de material docente para la enseñanza de electromagnetismo en materiales avanzados

Memoria ID-0246. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2016-2017

Micromagnetic Modeling of All Optical Switching of Ferromagnetic Thin Films: The Role of Inverse Faraday Effect and Magnetic Circular Dichroism

[EN] There is a lot of experimental evidence of All Optical Switching (AOS) by applying ultrashort laser pulses on ferromagnetic thin films with perpendicular magnetic anisotropy. However, the physical origin behind these processes remains under debate. In addition to the heating caused by the laser pulses, the Inverse Faraday Effect (IFE) and Magnetic Circular Dichroism (MCD) have been proposed as the most probable phenomena responsible for the observations of helicity-dependent AOS. Here, we review the influence of both phenomena by means of realistic micromagnetic simulations based on the Landau–Lifshitz–Bloch equation coupled to the heat transport caused by the laser heating. The analysis allows us to reveal the similarities and differences between both effects. While both mechanisms may lead to the local inversion of the initial magnetic state of a ferromagnetic sample submitted to a train of circularly polarized laser pulses, the Inverse Faraday Effect proves to be more efficient for nucleation and domain wall movement and it reproduces more accurately the different magnetic configurations that the experiments report for different values of the fluence of the laser beam.Project No. MAT2017-87072-C4-1-P from Ministerio de Economía y Competitividad of the Spanish Government Project No. SA299P18 from the Consejería de Educación of Junta de Castilla y León Project MagnEFi, Grant Agreement 860060 (H2020-MSCA-ITN-2019) funded by the European Commission

Magnetic Nanoparticles of iron oxide as matrices from controlled release

In this paper is carried out preparation of magnetites by different methods, co-precipitation and solvothermal, and its subsequent coating with mesoporous silica. Also, have been characterized using various characterization techniques: XRD, FT-IR, adsorption-desorption of N2 at - 196 ° C, SEM and magnetization curves. The results obtained indicate that the best method is the solvothermal since it allows to obtain uniform nanoparticles, small size with spherical morphology and more magnetism, which makes them suitable to be used as matrice of controlled releaseEn este trabajo se ha llevado a cabo  la preparación de magnetitas  por distintos métodos, coprecipitación y solvotermal,  y su posterior  recubrimiento con sílice mesoporosa. Asimismo, se han caracterizado utilizando diferentes técnicas: DRX, FT-IR, Adsorción-desorción de N2 a -196ºC, curvas de magnetización y SEM. Los resultados obtenidos  indican que es el método solvotermal el que permite obtener nanopartículas homogéneas, de pequeño tamaño, con morfología esférica y mayor magnetismo, propiedades que las hace idóneas para ser utilizadas como matrices de liberación controlad

Elaboración de recursos digitales en la asignatura Electromagnetismo I

Memoria ID-0058. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2015-2016

Desarrollo de experimentos para la visualización de fenómenos básicos en magnetismo

Memoria ID-0036. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Elaboración de material docente para la enseñanza de la Radiación y Propagación Electromagnéticas en la Física de las Comunicaciones

Memoria ID12-0135. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013

Creación de Trabajos de Fin de Grado en Física de carácter experimental

Memoria ID-002. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014