Journal of Optoelectronics and Advanced Materials Vol. 6, No. 2, June 2004, p. 541 - 550 INVITED PAPER FERROMAGNETIC RESONANCE IN NANOMETRIC MAGNETIC SYSTEMS D. S. Schmool * , R. Rocha, J. B. Sousa, J. A. M. Santos, G. N. Kakazei a , J. S. Garitaonandia b , D. Martín Rodríguez b , L. Lezama c , J. M. Barandiarán d IFIMUP and Departamento de Física, Universidade do Porto, Rua do Campo Alegre 687, P – 4169 007 Porto, Portugal a Department of Physics, Ohio State University, Ohio, USA b Fisika Aplikatua II saila, Euskal Herriko Unibersitatea (UPV/EHU), Apartado 644, 48080 Bilbao, Spain c Departamento de Química Inorgánica, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain d Departamento de Electricidad y Electrónica, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain Nanometric magnetic systems are of growing importance, displaying novel magnetic properties which are of both fundamental scientific interest as well as of practical importance. There are several types of system which can be classified as nanometric, which depend on the fabrication process, for example, amorphous / nanocrystalline alloys, immiscible alloys (e. g. Co – Cu), nanostructured films and discontinuous multilayer systems. In whatever case, magnetic confinement effects and the interactions between magnetic particles, via an intervening phase, give rise to the particular magnetic behaviour and properties of the system in question. Ferromagnetic resonance (FMR) is a powerful technique for the study of magnetic properties and has been applied to many different types of magnetic system. FMR essentially measures the internal effective field to which a spin system is subject and as such can reveal useful information on fundamental magnetic properties such as the g – factor, magnetisation, magnetocrystalline anisotropies and shape effects. In the present paper we present experimental results of FMR studies of FeZrCuB amorphous/nanocrystalline alloy, FeAl cluster systems and the discontinuous multilayer system Al 2 O 3 [CoFe(t)/Al 2 O 3 ] 10 , where t is the effective thickness, ranging from 7 to 13 Å. (Received April 26, 2004; accepted June 3, 2004) Keywords: Ferromagnetic resonance, Nanostructured magnetic materials, Discontinuous multilayers 1. Introduction In a magnetic resonance experiment, a spin, whether electronic or nuclear, will preccess about the direction of an applied magnetic field when the resonance condition is satisfied by the application of the appropriate strength magnetic (static and rf) field. In the case of nuclear spins this is termed nuclear magnetic resonance (NMR), while in the case of electronic spins the phenomenon is labelled in function of the type of material in question. For example, in paramagnetic materials it is referred to as electron paramagnetic resonance (EPR), also known as electron spin resonance (ESR) and in ferromagnetic materials as ferromagentic resonance (FMR). There are further classifications, such as antiferromagnetic resonance (AFMR) and spin wave resonance (SWR), which apply to antiferromagnetic and ferromagnetic systems (where confinement effects via magnetic boundaries can permit the excitation of standing spin wave modes of oscillation), respectively. * Corresponding author: dschmool@fc.up.pt