Superparamagnetism is a phenomenon observed in small magnetic nanoparticles where thermal fluctuations are sufficient to randomly flip the direction of magnetization. This occurs because the energy barriers to reorientation are comparable to the thermal energy at room temperature. Superparamagnetic nanoparticles exhibit magnetic properties only in the presence of an external magnetic field and show no remanent magnetization when the field is removed, making them ideal for applications where reversible magnetization is required.
