Sol-gel synthesized Ba-Nd-Cd-In nanohexaferrites for high frequency and microwave devices applications

Abstract

Nanocrystalline cadmium and indium substituted barium M-type hexagonal ferrite-based nanomaterials were prepared via sol-gel auto-combustion technique for studying the electrical, dielectric and conductivity characteristics of prepared samples such as dc resistivity, dielectric constant (ε’), dielectric loss (tan δ) and ac conductivity (σac) with the usage of different characterizing techniques like keithley 2611 two probe system and impedance analyzer. The room temperature dc resistivity of synthesized samples increases for lower concentrations i.e. x = 0.1 of Cd2+/In3+ but for the higher concentrations i.e. x = 0.2, it starts decreasing consequently. The temperature dependent dc resistivity also showing a decreasing trend as a function of temperature which continuously indicating the semi-conducting behaviour of BaM hexagonal nanohexaferrites. The room temperature dielectric characteristics was investigated as a function of logarithmic frequency and it can be explained on the basis of Maxwell Wagner model and space chare polarization. From the dielectric measurements, the dielectric constant (ε’) was found to be increasing with the increasing logarithmic frequency working as good energy storage material. The dielectric loss (tan δ) was found to be decreasing for the undoped sample (x = 0.0) but for the undoped samples (x = 0.1–0.2), it starts increasing in a very minute manner. Therefore, such materials of high increasing dielectric constant with minute values of dielectric losses make it suitable for the high frequency, energy storage and microwave devices application.