Magnetic and Dielectric Properties of Fe 3 O 4

Dielectric constant and the initial permeability of Fe 3 O 4 have been measured from 4.2 K to room temperature. Magnetic and dielectric relaxations were observed in the temperature range of 30 to 60 K. These relaxations were considered to be caused by the transfer of electron between ferrous and ferric ions. The magnetic permeability showed a peak at the Verwey transition temperature T v in Fe 3 O 4 sintered samples. Magnetic loss showed an anomalous rise at T v . The magnetization at the field of 8.3 kOe also showed a rise at T v . This anomalous magnetic behavior is considered to be caused by the change of easy axis of magnetization at T v .