The ferromagnetic
nano-particles are coated with a surfucat to prevent
their agglomeration (due to and magnetic forces). Although
the name may suggest otherwise, ferrofluids do not display
ferromagnetizm , since they do not retain magnetisation in the
absence of an externally applied field. In fact, ferrofluids
display paramagnetism , and are often referred as being
"superparamagnetic" due to their large magnetitc
suspensionities.
