Magnetoactive feature of in-situ polymerised polyaniline film developed on the surface of manganese-zinc ferrite

► In-situ grown PANI film on the surface of MnZn ferrite exhibits magnetoactive properties. ► Ferrite accelerates PANI growth by sorption of paramagnetic anilile oligomers on domain walls. ► Pinning of domain walls restricts their mobility in magnetic fields. ► Pinning forces are strong enough to induce magnetic anisotropy in low-anisotropy MnZn ferrite. ► Stress-induced magnetic anisotropy increases inner demagnetising factor of coated ferrite particles.