The microstructure and magnetic properties of Ni0.4Zn0.6Fe2O4 films prepared by spin-coating method

Nickel zinc ferrite (Ni0.4Zn0.6Fe2O4) films on Si (100) substrate were synthesized using a spin-coating method. The crystallinity of the Ni0.4Zn0.6Fe2O4 films with the thickness of about 386 nm became better as the annealing temperature increased. The films have smooth surface, relatively good packing density and uniform thickness. The volatilization of Zn is serious at 900 °C. With the increase of annealing temperature, the saturation magnetization M s increases in the temperature ranging from 400 to 700 °C, however, decreases above 700 °C, and the coercivity H c increases in the temperature range 400–800 °C, decreases above 800 °C. After annealed at 700 °C for 2 h in air with the heating rate 2 °C/min, the film shows a maximum saturation magnetization M s of 349 emu/cc and low coercivity H c of 66 Oe. The M s is higher than others which prepared by this method, however, the H c is lower. The M s of Ni0.4Zn0.6Fe2O4 films annealed at 700 °C increases with increasing annealing time and the H c changes slightly.