Preparation and characterization of nickel manganese ferrite

Arrays of Ni1-xMnxFe2O4 (x = 0.0, 0.25, 0.5, 0.75) nanowires with an average diameter of about 80 nm are prepared by porous anodic aluminum oxide membrane poured sol technique. X-ray diffraction analysis shows that the nickel manganese ferrites nanowires with cubic spinel structure are synthetized. Scanning electron microscopy and transmission electron microscope images indicate that the nanowire arrays are composed of prolate spheroids with different crystal orientations. Magnetic measurements show that saturation magnetization increases and then decreases with Mn increasing. The change is related to the location and the substitution of ion in spinel structure. Compared with of block material NiFe2O4, the saturation magnetization of nickel ferrite nanowire arrays is low. This is due to the fact that the noncollinear magnetic structure in nanowire arrays become predominant.