Superparamagnetic behavior of antiferromagnetic six lines ferrihydrite nanoparticles

Magnetic behavior of 5 nm antiferromagnetic six lines ferrihydrite particles is reported. The magnetization as a function of applied magnetic field data at 100 K are fitted to the modified Langevin function without and with considering a distribution in particle magnetic moment covering different ranges of applied magnetic field strength. The resulting fit parameters are analyzed and compared. In the first case fit parameters are found to be strongly dependent on the strength of applied magnetic field. But the fit parameters are found to be independent of applied magnetic field strength in the later case.