Tailoring the electrical and dielectric properties of ZnO nanorods by substitution

ZnO nanorods with substitution of different transition metal ions (Hg, Cd, Cu, Mn and Ni) were prepared by simple thermal decomposition process. Structural and microstructural properties of all the as-synthesized samples were characterized using the X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrical conductivity and dielectric properties of all the samples have been studied over a wide frequency range 1 Hz to 1 MHz by complex impedance spectroscopic measurements at room temperature. The dc conductivity (σ_dc) was extracted for all the samples by extrapolating frequency independent region of respective ac conductivity (σ_ac) plot. Frequency variation of the dielectric loss (tanδ) of the samples has been obtained from impedance data and the same plot was further used to extract dielectric relaxation time (τ). Reasons for the tailored conductivity as well as relaxation time because of substitution in ZnO nanorods were discussed in detail.