Improved microwave absorption properties of TiO₂ and Ni_0.53Cu_0.12Zn_0.35Fe₂O₄ nanocomposites potential for microwave devices

Nanostructured xTiO₂+(1-x) Ni_0.53Cu_0.12Zn_0.35Fe₂O₄ nanocomposites (where 0 ≤ x ≤ 1) were prepared by a low temperature microwave-hydrothermal (M-H) method at 165°C/45 min. Microwave sintering (MS) technology has been applied in the preparation of nanocomposites. Several kinds of such systems have been fabricated by MS technology. The sintering time and temperature were reduced from 22 h to 1100°C for conventional sintering process to 30 min and 500°C for MS process, respectively. The addition of TiO₂ to Ni_0.53Cu_0.12Zn_0.35 ferrite increased the dielectric properties (ϵ′ and ϵ″). The imaginary part of permeability (μ″) was found to increase with an increase of TiO₂. The complex permittivity and permeability were collected by the vector network analyser and the absorbing properties were calculated according to transmission theory. The absorption peak shifted to higher frequencies with the substitution. The highest reflection coefficient value of -28 dB at 10.26 GHz was observed for the x = 0.5 sample. The microwave absorption band width of -10 dB with xTiO₂+(1-x) Ni_0.53Cu_0.12Zn_0.35Fe₂O₄ nanocomposites is effectively broadened compared with other ferrites. Based on the magnetic and microwave measurements xTiO₂+(1-x) Ni_0.53Cu_0.12Zn_0.35Fe₂O₄ may be a good candidate for electromagnetic materials and other practical applications like military and civil applications.