Memory in nanomagnetic systems: Superparamagnetism versus Spinglass behavior
arXiv:cond-mat/0606233 · doi:10.1103/PhysRevB.74.214410
Abstract
The slow dynamics and concomitant memory (aging) effects seen in nanomagnetic systems are analyzed on the basis of two separate paradigms : superparamagnets and spinglasses. It is argued that in a large class of aging phenomena it suffices to invoke superparamagnetic relaxation of individual single domain particles but with a distribution of their sizes. Cases in which interactions and randomness are important in view of distinctive experimental signatures, are also discussed.
11 pages and 19 figures