Magnetic permeability stability of composite material with nominal composition Ni0.6Fe2.4O4

A composite material with a nominal composition of Ni 0.6 Fe 2.4 O 4 was prepared by the solid-phase reaction method. X-ray diffraction analysis shows that the product is composed of α-Fe 2 O 3 and a solid solution of Fe 3 O 4 and NiFe 2 O 4 . Although α-Fe 2 O 3 non-magnetic phase reduces the saturation magnetization, it greatly improves the temperature and frequency stability of magnetic permeability. Based on the measurement results of the amplitude permeability in the range of −60 °C to 100 °C, the temperature coefficient α μ and specific temperature coefficient β were calculated. α μ and β of the composite material are 7.15 × 10 - 5 / ° C $\times {10}^{-5}{/}^{°}\mathrm{C}$ and 8.6 × 10 - 6 / ° C $\times {10}^{-6}{/}^{°}\mathrm{C}$ , respectively, which are much smaller than α μ (1.26 × 10 - 3 / ° C ) $\times {10}^{-3}{/}^{°}\mathrm{C})$ and β (9.5 × 10 - 5 / ° C ) $\times {10}^{-5}{/}^{°}\mathrm{C})$ of NiFe 2 O 4 . At the same time, the magnetic spectrum curves show that the real part of the complex permeability μ ' basically remains unchanged within the measurement frequency range ( f  < 10 6 Hz). This improvement in temperature and frequency stability is attributed to the effect of the α-Fe 2 O 3 phase.