Magnetic properties of RF-sputtered NiO and Ni0.8Fe0.2O1-δ samples grown on SiO2/Si substrates

ABSTRACTMagnetic properties of RF (Radio Frequency)-sputtered NiO and Ni0.8Fe0.2O1-δ films made at low or high oxygen (O) sputtering pressures were studied and discussed. The X-ray diffraction pattern shows that all samples have a NaCl-type structure. The magnetic properties were measured as a function of magnetic field at different temperatures using the PPMS Model-6000. All samples contain a small magnetic moment resulting in a saturation magnetisation of 1–5 emu/cm3. A hysteresis curve at fields below 500 oersted (Oe), and a high-field magnetic slope were observed in all samples. Low-field hysteresis and high magnetic slope depend on the temperature. For a low O flow sputtered sample , the high-field slope increases with increasing temperature, and for a high O flow sputtered sample , the high-field slope decreases with increasing temperature. The low-field hysteresis increases for low O flow sputtered samples but increases for high O flow sputtered samples.