The influence of annealing temperature on the structure and optical properties of Gd2Zr2O7 nanostructures prepared by chemical bath deposition method

Abstract

Gadolinium zirconate (Gd2Zr2O7) powders were prepared for the first time using chemical bath deposition (CBD) method. In this study, the chemical bath deposition (CBD) method was employed due to its simplicity, cheap, low temperature, versatile and it gives better homogeneity. The effect of annealing temperature (Ta) on the thermal, structural, morphological, and optical properties were investigated. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA) showed that the material is thermally stable between 400 and 900 °C. The X-ray diffraction (XRD) results confirmed the cubic Gd2Zr2O7 phase with hexagonal ZnO secondary peaks. Scanning electron microscopy (SEM) results revealed the transformation of irregular particles to hexagonal-like structure shape with an increase in Ta. Energy dispersive x-ray spectroscopy (EDS) analysis confirmed the presence of the expected elements. Transmission electron microscopy (TEM) confirmed the nano-nature of the prepared powders. Ultraviolet-visible spectroscopy (UV-Vis) spectra showed a slightly red shift with an increase in Ta. The photoluminescence (PL) results revealed that the emission intensity and peak position in UV region highly depends on the Ta. It was also noted that both secondary peaks from hexagonal ZnO and Ta regulates the defects emission. The international illumination (CIE) color chromaticity showed that the color shifts from blue to yellow-greenish with an increase in Ta. The approach in the present study opened a new way to tune band gap and luminescence intensity of Gd2Zr2O7.