Superparamagnetism's a form of magnetism. A superparamagnetic material's composed of small ferromagnetic clusters (for example crystallites), but where the clusters are so small that they can randomly flip direction under thermal fluctuations. As a result, the material as a whole isn't magnetized except in an externally applied magnetic field (in that respect, it's like paramagnetism). Description Specifically, superparamagnetism's a phenomenon in which magnetic materials may exhibit a behavio… (More on Superparamagnetism)