Structure and magnetic properties of Ni0.7Mn0.3Fe2O4 nanoparticles doped with La2O3

Abstract

Ni0.7Mn0.3LaxFe2–xO4 (x = 0, 0.04, 0.06, 0.08, 0.1) ferrite powders with nanosize well-developed spinel phases were prepared by the emulsion method. The growth of particles, the structure and the magnetic properties were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy and a vibrating sample magnetometer (VSM). Furthermore, the influence of La2O3 on the magnetic properties of Ni0.7Mn0.3LaxFe2–xO4 ferrites powders has been investigated extensively. Experimental results show that La3+-doped Ni0.7Mn0.3Fe2O4 ferrites have higher special saturation magnetization Ms than that of Ni0.7Mn0.3Fe2O4 ferrite when sintered at 900 °C. Ni0.7Mn0.3La0.06Fe1.94O4 ferrite nanoparticle with particle size of 11 nm has superparamagnetic. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)