Thin films of NiFe2O2 were fabricated on MgO (001) and MgAl2O2 (MAO) (001) substrates by reactive radio frequency magnetron sputtering and were evaluated with regards to their electrical and magnetic properties. A saturation magnetization of 285 emu/cm3 was obtained with a 30 nm thick film grown on an MAO substrate at an oxygen flow rate, Q, of 9 sccm. This enhanced magnetization was found to be due to a normal spinel arrangement at the interface. From the thickness dependence of the magnetization, the intrinsic magnetization was determined as 241 emu/cm3 with the enhancement region estimated to be around 3/4 of the lattice constant, thus providing 8 μB/f.u. The magnetization of those films grown on an MgO substrate exhibited remarkably smaller amplitudes to those of the MAO substrates. It is suggested that this substrate-dependent magnetization can be attributed to the number of antiphase boundaries. The resistivity was found to increase with Q, with a resistivity state in the same order as that of the bulk achieved with films prepared in which Q was greater than 10 sccm.
- MgAlO (MAO) substrate
- MgO substrate
- NiFeO epitaxial thin film
- reactive sputtering.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering