Dielectric investigation and material properties of almond gum thin films deposited by spray pyrolysis

In this paper, we study the dielectric and material properties of almond gum, a natural biopolymer material collected from almond trees. The dielectric properties are investigated by mean of impedance spectroscopy in the ranges of frequency 40 Hz-10MHz and temperature 300 K–400 K. The resulting responses provided valuable information about the material and revealed that the dielectric parameters are both temperature and frequency dependent. The calculated dielectric constant is around 8 at temperature T = 300 K and frequency f = 1 kHz. UV–visible spectrum of the almond gum thin films recorded from 300 nm to 2500 nm, showed a high transmittance with an optical band gap around 3.4eV. X-ray fluorescence showed that almond gum contained oxides such as CaO, SiO2, K2O, etc, with a significant concentration of CuO (63.72%) and several other chemical elements in trace such as strontium, rubidium, chlorine, cadmium, sulfur, etc. Thermal properties studies such as thermogravimetric analysis and differential scanning calorimetry conducted on almond gum powder revealed two stages of decomposition with a glass transition at 58.5 °C. In order to study the surface properties of almond gum thin films, we have carried out contact angle measurements and scanning electron microscopy analysis. The results showed hydrophobic surfaces. Our findings in this study lead to conclude that almond gum may be an interesting candidate for electronic applications especially for gate dielectric and encapsulating layer.