Non-equilibrium dynamics in superspin glass systems.

Peddis D.
  Giovedì 14/09   16:00 - 19:00   Aula A224   II - Fisica della materia
In a magnetic nanoparticles system the thermal evolution of the magnetization dynamics depends on the strength and nature of the inter-particle interactions. In sufficiently concentrated nanoparticle systems, strong dipolar interaction combined with random orientation of anisotropy axes determine a competition between different moment alignments leading to a collective freezing of particle moments in a disordered magnetic state, known as superspin glass (SSG), below a characteristic glass temperature ($T_{g}$). In this contribution, the non-equilibrium dynamics of interacting magnetic nanoparticles will be discussed by means of memory and rejuvenation experiments, showing the validity of the principle of superposition for a SSG system.