Effect of thickness on magnetic and microwave properties of RF-sputtered Zn-ferrite thin films

Zinc ferrite thin films of varying thickness were deposited at ambient temperature using RF-magnetron sputtering. The films were annealed at temperatures in the range 250 °C to 650 °C in air for 2 hrs. The magnetization of the film was observed to depend on the average grain size and also on thickness of the film. It was found that thermal annealing reduces the peak to peak ferromagnetic resonance (FMR) line width. A low in-plane line width of 195 Oe and a line width of 170 Oe in perpendicular configuration was observed for a 240 nm thickness film annealed at TA=450 °C.