Ni doped ZrTiO₄ ceramics for dielectric resonator applications

Structural, morphological, dielectric and electrical properties of Zr_1−xNi_xTiO₄ (x = 0, 0.05, 0.10, 0.15 and 0.2) are studied in this work using X-ray diffraction, field emission scanning electron microscopy and impedance spectroscopic measurements, respectively. The compositions were prepared using sol–gel auto-combustion method and observed to possess the orthorhombic structure with a space group, Pnab 60. The Fourier transform infrared spectroscopy inveterated that the combustion was complete. Field emission scanning electron microscopic study reveals that the homogeneity and density of the particles increase with increasing doping concentration. Grain size increases with increasing Ni contents i.e. from 0.25 to 0.5 µm, mostly depicting irregular morphology. Energy dispersive X-ray technique confirmed the presence of Ni, Zr, Ti and O in the prepared materials. Dielectric parameters i.e. dielectric constant and loss decreases with increasing frequency. Conductivity increases with increasing Ni contents and with the increase in frequency. Complex impedance plot shows a single semicircle corresponding to ZrTiO₄ and Ni-doped ZrTiO₄ which determines the dominancy of grain boundary resistance at low frequency. Electric modulus reveals the real dielectric relaxation process.