M. Ubaidullah, T. Ahmad
Keywords: nanostructures, chemical synthesis, X-ray diffraction, transmission electron microscopy, dielectric properties
Summary:Monophasic nanoparticles of Ba1-xPbxZrO3 (x = 0.05, 0.10, 0.15 and 0.20) have been successfully prepared by simple inverse microemulsion method at 900ºC for the first time. These nanoparticles were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), energy dispersive analysis of X-rays (EDAX), BET surface area and dielectric properties. The contraction of lattice in XRD led to the formation of monophasic solid solutions of (Ba,Pb)ZrO3. Mixed shape (spherical, cubic and hexagonal) particles with average grain size in the range of 42-70 nm revealed by TEM. The chemical compositions of the solid solutions have been established by EDAX studies. The surface area of as-prepared nanoparticles was found to be in the range of 64-157 m2g-1 and corroborated well with the TEM studies. The dielectric constant was found to increase (27.2 to 89.5) on increasing the Pb2+ ion concentration (0.05 to 0.20), however, the dielectric loss was found to decrease (0.07–0.002) which suggests the good dielectric characteristics of nanoparticles. Suitable pore morphology and high temperature stability makes this material a prominent media to develop capacitive sensor. The novel nanostructured ceramic material has been utilized to fabricate parallel plate capacitive sensor for sensing relative humidity. It is observed that the capacitance value of the sensor increases with increase in humidity and the nanoparticles can be suitable for vapor sensing application.