Nickel Ferrite Thin Films Research Articles

Preparation of cobalt doped nickel ferrite thin films on optical fibers by dip-coating technique

Cobalt doped NiFe 2O 4 thin films were synthesized using dip-coating wet-chemical process using a solution of iron (III) nitrate dissolved in ethylene glycol and 2-methoxyethanol. Films coated on flat (alumina plates, fused silica, slide glass) substrates and optical fibers were dense and without defects. The onset of the film crystallization was between 450 and 500 °C and crystallinity increased with increasing processing temperature. Magnetization of ferrite films on optical fibers was nearly reversible in external magnetic field H ext up to about 2.4 kA/m even without preceding AC demagnetization. The magnetization of 255 × 10 −3T for Ni 0.99Co 0.01Fe 2O 4 films processed at 750 °C for 2 h was observed. No further improvement in magnetic properties was found beyond this temperature.

Defects in nickel ferrite thin films grown by chemical vapour deposition

Thin single-crystal films of nickel ferrite have been grown on magnesia substrates. The structure of the films has been examined using X-ray diffraction, scanning electron microscopy and transmission electron microscopy and diffraction. The films are characterized by arrays of planar faults on {110} due to faults in cation arrangements in the nickel ferrite spinel lattice. The origin of these defects is discussed.