Microwave properties of Al and Mn doped nickel ferrites at Ku band frequencies

•Influence of aluminum and manganese doping on various properties of Nickel ferrite.•Isolation, insertion loss and return loss were undertaken at Ku band (12–18 GHz) frequencies.•Qualitative explanation for the various observed phenomena was given.

To investigate the influence of aluminum and manganese doping on structural, electrical, magnetic and microwave behavior of nickel ferrites, the samples were prepared by citrate sol–gel method. Samples were characterized by X-ray diffractometer using Rietveld refinement technique and are found to have cubic structure with space group Fd3¯m. A systematic investigation of magnetization, permeability, permittivity and microwave properties such as isolation, insertion loss and return loss was undertaken at Ku band (12–18 GHz) frequencies. A qualitative explanation for the various observed phenomena was given.