Study of the magnetic properties of nanoparticles interacting with surface acoustic

Abstract

In this work we design and build from zero, a device with the aim of studying the spin-phonon interaction in magnetic nanoparticles. New techniques to manipulate the magnetic moments of nanostructures are demanding to be studied. Surface acoustic waves (SAWs) are an excellent candidate as they offer a dynamic and tunable mechanism for the control of low energy excitations. The final goal of the project is to get closer towards acousto-magnetic devices as well as the better understanding of the fundamentals of the interaction. Both the design and building of the samples have been made by us at Paul-Drude-Institut für Festkörperelektronik in Berlin, with the idea of having an exhaustive control of all the parameters. Fe2O3 magnetic nanoparticles were embedded in a SiO2 matrix, and deposited in a piezoelectric substrate (LiNbO3) between two interdigital transducers (IDTs) that generate SAWs when they are connected to a source of microwaves. Magnetic measurements are taking place in a SQUID magnetometer at University of Barcelona, consisting in studying the magnetization dynamics when applying SAWs of different frequencies and powers to the sample. The effects of the temperature and the external applied field are also studied.