Fabrication and characterization of CuO-doped Ni-Co-Zn ferrite composites for RF applications.

With the recent advancements related to imminent rollout of 5G and IoT technologies, there is a growing demand for soft magnetic materials for different applications such as antennas, circulators, inductors, interference suppressors and wireless power transfer etc. Ni-Co-Zn ferrites exhibit excellent soft magnetic properties such as high resistivity, high permeability and low magnetic loss for RF applications. To meet the performance specifications for aforementioned applications, Ni-Co-Zn sheets with a high permeability and low magnetic loss is desired. In this work, we present a novel method to prepare thin Ni-Co-Zn ferrite sheets with high permeability and low magnetic loss for RF antenna applications. Ni-Co-Zn ferrite powders were prepared by solid state synthesis. Different CuO wt% were doped in Ni-Co-Zn samples. Toroidal samples made from powders under different level of hydraulic force were sintered in air. Enhancement in the resonance frequency was achieved by doping of copper oxide (0 to 10 wt%) in Ni-Co-Zn ferrite. The permeability decreases from 7 (0 wt%) to 5.3 (10 wt%) along with increase in resonance frequency from 300 to 530 MHz. Magnetic loss of 0.04 achieved at 530 MHz frequency. Ni-Co-Zn sheets were prepared with same optimized conditions for RF antennas.