Possibility of NiCuZn Ferrites Composition for Stress Sensor Applications

NiCuZn ferrite with composition of (NCu0.10Zn0.60F) (where , 0.02, 0.04, 0.06, 0.08, and 0.10) was prepared by the conventional ceramic double sintering technique. The formation of single phase was confirmed by X-ray diffraction. The microstructural features were also studied by electronic microscopy and are reported. Initial permeability measurements on these samples were carried out in the temperature range of 30 to 300°C. The effect of external applied stress on the open magnetic circuit type coil with these ferrite cores was studied by applying uniaxial compressive stress parallel to the magnetizing direction and the change in the inductance was measured. The variation of inductance (ΔL/L)% increases up to certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that the Ni0.42Cu0.10Zn0.60Fe1.76O3.76 and Ni0.44Cu0.10Zn0.60Fe1.72O3.72 samples are found to be suitable for inductive stress sensor applications.