Study of ZnAl2O4 spinel nanoparticles synthesized using gelatin as organic precursor

Abstract

In this work, zinc aluminate spinel powders were prepared by a fast, simple, eco-friendly and low-cost modified Pechini method using commercial gelatin as the organic precursor. The materials were calcinated at 600, 700 and 800 °C and characterized by thermogravimetric analysis, in situ and ex situ X-ray diffraction (XRD), N2-adsorption/desorption isotherms and scanning electron microscopy. The results showed that single phase ZnAl2O4 particles with spinel structure were successfully obtained resulting in a high purity, nanometric, homogeneous and mesoporous materials. The in situ XRD results showed that the crystalline spinel structure of ZnAl2O4 started forming at a temperature lower than 600 °C, revealing powders with crystallite size smaller than 40 nm, which increased with increasing the temperature (91% of increase between 600 and 800 °C). The effect of calcination time showed that the materials calcinated at 600 °C for 3 h presented the higher percentage of crystallite growth due to the increase of crystallinity. The ZnAl2O4 samples retained their pore size up to 700 °C.

Synthesis and investigation of dielectric properties of nanoceramic composite material for microwave applications

“…Table 1 shows the comparison of reported works with the present one. The reported crystallite size was observed to be in the range of 16–40 nm [21, 26–30], whereas extremely small crystallite ∼3.7 nm was reported which can be assigned to the hydrothermal process along with the choice of high calcination temperature of 1200°C [31]. In the present study, we first synthesised the TiO 2 nanoparticles by chemical route which was further employed in the sol–gel synthesis of ZnAl 2 O 4 TiO 2 .…”