Role of Cu2+ ions substitution in magnetic and conductivity behavior of nano-CoFe2O4

•Copper doped cobalt ferrite nanopowders were prepared at low temperature combustion route.•Characterization by PXRD, SEM and FTIR techniques confirms the nanoregime.•Substitution of Cu2+ to cobalt ferrite changes the magnetic and electrical properties.•Synthesized compounds were suitable for high frequency applications.

Cobalt copper ferrite nanopowders with composition Co1−xCuxFe2O4 (0.0 ⩽ x ⩽ 0.5) was synthesized by solution combustion method. The powder X-ray diffraction studies reveal the formation of single ferrite phase with particle size of ∼11–35 nm. Due to increase in electron density with in a material, X-ray density increase with increase of Cu2+ ions concentration. As Cu2+ ions concentration increases, saturation magnetization decreases from 38.5 to 26.7 emu g−1. Further, the squareness ratio was found to be ∼0.31–0.46 which was well below the typical value 1, which indicates the existence of single domain isolated ferrimagnetic samples. The dielectric and electrical modulus was studied over a frequency range of 1 Hz to 1 MHz at room temperature using the complex impedance spectroscopy technique. Impedance plots showed only one semi-circle which corresponds to the contributions of grain boundaries. The lower values of dielectric loss at higher frequency region may be quite useful for high frequency applications such as microwave devices.

Graphical abstractVariation of dielectric loss tangent (tan δ) with frequency for Co1−xCuxFe2O4 nanopowder.Figure optionsDownload full-size imageDownload as PowerPoint slide