TABLE OF CONTENTS Understanding the magnetic properties of small magnetic elements has become a major challenge in fundamental physics, involving both static and dynamic properties. The importance to technological applications such as high-density magnetic storage is also clear. The investigation of such small magnetic structures relies increasingly on magnetic imaging techniques, since the relevant properties can vary over length scales from micrometers to nanometers. This chapter describes an experimental method for measuring the fast magnetic phenomena in lithographically fabricated magnetic elements in the picosecond temporal regime and with sub-micrometer spatial resolution. The method employs stroboscopic scanning microscopy and is capable of measuring simultaneously all three components of the magnetization vector. This technique allows direct insight into the spatiotemporal evolution of dynamic processes, including ferromagnetic resonance and magnetization reversal in small magnetic elements.
Magnetic phenomena on short time scales are different in many aspects from the static case [1] , [2]. Moreover, the fast magnetic phenomena in small patterned elements have little relation to that in continuous films, due to the magnetostatics of element edges, which modify the equilibrium states of the elements in terms of the magnetic moment distribution [3] [5]. From an application point of view, it has become crucial to understand reversal dynamics on fast (in the nano- and picosecond range) time scales in magnetic elements with dimensions in the micrometer size regime and below. This is owing to the increasing demands on conventional storage technologies and for newer approaches such as...
