Instituto de Nanociencia y Nanotecnología, CNEA-CONICET, Centro Atómico Bariloche & Instituto Balseiro, Universidad Nacional de Cuyo–CNEA, San Carlos de Bariloche, Argentina.
«Imaging Magnetic Domains with PMOKE Microscopy: Exploring Universal Aspects of Domain Wall Dynamics»
Magnetic materials have been known for more than two millennia, but a microscopic understanding of their properties only began to emerge in the late 19th and early 20th centuries, with the introduction of key concepts such as magnetic anisotropy and domains. Since then, progress has gone hand in hand with the development of experimental techniques enabling increasingly detailed characterization of magnetic behavior.
In this talk, I will introduce the basics of magneto-optical characterization, focusing on polar magneto-optical Kerr effect (PMOKE) microscopy—a powerful, non-invasive tool to image magnetization processes in thin films with perpendicular magnetic anisotropy. PMOKE provides direct access to the magnetic “topography” of these systems and its evolution under applied magnetic fields, making it possible to study the dynamics of magnetic domain walls (interfaces between domains) across different regimes.
I will discuss how creep, depinning, and flow arise from the interplay between driving forces, disorder, and elasticity associated with microscopic exchange interactions. These dynamics can be linked to the geometrical properties of the interface and understood within the general framework of driven disordered systems, revealing universal scaling behavior.
Overall, the talk aims to highlight how magneto-optical microscopy serves not only as a characterization tool, but also as a bridge between experimental observations and concepts from statistical physics, enabling the exploration of universal phenomena in magnetic systems.