Magnetic Properties of ${[{\rm SnO}_{2}/{\rm Cu}{-}{\rm Zn} {\rm ferr\ite}]}_{\rm n}$ Multilayers

Multilayers (ML) of [SnO₂/Cu-Zn ferrite]_n<;/sub>; were fabricated by rf-sputtering. The effect of number of bilayers, n, on its magnetic properties is studied. The rotational dependence of the ferromagnetic resonance (FMR) parameters depict the anisotropic nature of the ML. The anisotropy energy is positive and increases with increasing n, indicating an out of plane anisotropy. The hysteresis for n=5 depicts the ferromagnetic nature of the sample with saturation magnetization (M_s) of 61 emu/cc CZF. With increase in n the hysteresis loop display coercivity along with a paramagnetic component indicating the existence of antiferromagnetic interactions which reduces the net magnetization of the ML to 20 emu/cc CZF for n=15. The magnetization data supports the conclusions drawn from the FMR studies. The observed magnetic properties are ascribed to the lack of spin correlations in the interfacial region of the ML.