Magnetization of Low Temperature Phase of Fe3O4

Saturation magnetization of low temperature phase of Fe 3 O 4 was accurately measured for the monoclinic single phase using automatic magnetic pendulum. The spontaneous magnetization just below T V was found to be about 0.1% smaller than that just above T V , even after the extrapolation to the infinitely large magnetic field which is applied parallel to the cubic [001]. The saturation magnetization at 0 K was determined to be 97.77 emu/g (4.05 µ B /Fe 2+ ) after extrapolation to 0 K by using the T 3/2 law. The magnetization curves were measured along the principal axes of monoclinic phase and compared with the calculation using the available anisotropy constants. The agreement was good except for low magnetic field region in all the directions.