  Varying the substrate temperature changes structural and magnetic properties
of spinel ferrite NZFO thin films. XRD of films grown at different temperature
display only 004 reflections, without any secondary peaks, showing growth
orientation along the c axis. We find an increase in crystalline quality of
these thin films with the rise of substrate temperature. The surface topography
of the thin films grown on various growth temperatures conditions reveal that
these films are smooth with low roughness, however the thin films grown at 800
C exhibit lowest average and rms roughness among all thin films. We find iron
and nickel to be more oxidized i,e greater Fe and Ni content in films grown and
annealed at 700 C and 800 C, compared to those grown at lower temperatures. The
magnetic moment is observed to increase with an increase of substrate
temperature and all thin films possess high saturation magnetization and low
coercive field at room temperature. Films grown at 800 C exhibit a
ferrimagnetic paramagnetic phase transition well above room temperature. The
observed large magnetizations with soft magnetic behavior in NZFO thin films
above room temperature suggest potential application in memory, spintronics,
and multifunctional devices.
