Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2018, Tutors: Javier Tejada Palacios, Jaume Calvo de la Rosa
In this work, the magnetic properties of one Soft Magnetic Material (SMM) and one Soft Magnetic Composite (SMC) are studied as a function of different particle size distribution. X-Ray Diffraction (XRD) show that both samples consist on an iron core. The basic magnetic characterization of the samples is done by measuring the isothermal magnetization M(H) curves and zero field cool (ZFC) – field cool (FC) curves. The results show that, despite being magnetic iron particles, they present an extremely narrow hysteresis loop. Moreover, it has been seen that the higher the size distribution is, the greater the magnetic saturation is achieved. In order to study them from the point of view with more technological and industrial interest, their functional properties are measured in a wide frequency range. In this regard, Impedance Spectroscopy is used to measure their magnetic permeability between 1 kHz and 13 MHz while their dielectric constant is studied from 200 MHz to 20 GHz by using a Pulse Network Analyser (PNA). Finally, reflection loss measurements are performed in order to measure directly the energy absorbed in the range between 7 GHz and 10 GHz.