Magnetic properties of nanocrystalline Ni0.7Mn0.3Gd0.1Fe1.9O4 ferrite at low temperatures

Abstract Mossbauer spectra and magnetic measurement of Ni 0.7 Mn 0.3 Gd 0.1 Fe 1.9 O 4 ferrite were investigated by Oxford MS-500 Mossbauer spectrometer and superconducting quantum interference device (SQUID) magnetometer with a field 5 T. Ni 0.7 Mn 0.3 Gd 0.1 Fe 1.9 O 4 nanoparticles have a considerable coercivity of 1040 Oe when the test temperature is reduced to 2 K. Mossbauer spectra show that Ni 0.7 Mn 0.3 Gd 0.1 Fe 1.9 O 4 nanoparticles exhibit superparamagnetism at room temperature and ferrimagnetism at 77 K.