RESUMEN
In the present research work, bismuth ferrite mullite type Bi2Fe4-xZnxO9 (0.0 ≤ x ≤ 0.05) nanostructures are prepared by a chemical coprecipitation method and the effect of Zn doping concentration on the structural, surface topography, and dielectric properties is reported. The powder X-ray diffraction pattern of the Bi2Fe4-xZnxO9 (0.0 ≤ x ≤ 0.05) nanomaterial shows an orthorhombic crystal structure. Using Scherer's formula, the crystallite sizes of the nanomaterial Bi2Fe4-xZnxO9 (0.0 ≤ x ≤ 0.05) have been calculated and found to be 23.54 and 45.65 nm, respectively. The results of the atomic force microscopy (AFM) investigations show that spherical shape nanoparticles have grown and are densely packed around each other. AFM/scanning electron microscopy images, however, also illustrate that spherical nanoparticles transform into nanorod-like nanostructures with an increase in Zn concentrations. The transmission electron micrography images of Bi2Fe4-xZnxO9 (x = 0.05) showed elongated/spherical shape grains homogeneously distributed throughout the inside of the surface of the sample. The dielectric constants of Bi2Fe4-xZnxO9 (0.0 ≤ x ≤ 0.05) materials have been calculated and found to be 32.95 and 55.32. It is found that the dielectric properties improve with an increase in the Zn doping concentration, making it a good potential contender for multifunctional modern technological applications.
RESUMEN
In the present research work, Zn1-x Al x O thin films with varying proportions of Al (x = 0.00, 0.01, 0.02, and 0.03) are prepared by a chemical sol-gel spin-coating technique. The crystal structural, morphological, and humidity-sensing properties of the synthesized Zn1-x Al x O thin films, with varying concentrations of Al (x = 0.00, 0.01, 0.02, and 0.03), were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM); a special humidity-controlled chamber was designed for the humidity-sensing studies. In structural and phase analyses, XRD patterns of Zn1-x Al x O thin films show a hexagonal wurtzite crystal structure. The average crystallite sizes of Zn1-x Al x O thin films were calculated and found to be â¼18.00, 22.50, 26.30, and 29.70 nm using the X-ray diffraction (XRD) pattern. The surface morphology of Zn1-x Al x O Al (x = 0.00, 0.01, 0.02, and 0.03) thin films obtained from AFM micrographs analysis indicates the modification of the spherical grains into nanorods, which were distributed throughout the surface of the films. The SEM image of 3 wt % Al-doped ZnO nanomaterials also shows that spherical nanoparticles changed to nanorod-like structures with a high packing density. Furthermore, increasing the Al-doping concentration from 0 to 3 wt % in ZnO NPs shows lower hysteresis loss, less aging effect, and good sensitivity in the range of 9.8-16.5 MΩ/%RH. The sensitivity of the sensing materials increased with increasing Al-doping concentration, which is very useful for humidity sensors.
