Akademik Veri Yönetim Sistemi
Materials Today Communications, cilt.29, 2021 (SCI-Expanded)
© 2021 Elsevier LtdZeolites are spectacular natural minerals that can replace other expensive or hazardous materials in wide-range applications by virtue of their unique physico-chemical properties. In this study, a comprehensive investigation of the possible effects of low-energy mechanical ball milling on the dielectric response and electrical conduction mechanisms of natural clinoptilolite zeolites was carried out in 300–800 K temperature range through current-voltage (I-V) and capacitance-conductance (C-G) experimental measurements. Two samples were prepared; one with 1-hour hand grinding and another with 8-hours ball milling. Both samples exhibited a typical semiconductor behavior beyond 400 K and the conductivity obeyed Jonscher power law where transport mechanisms were governed by non-overlapping small polaron tunneling and correlated barrier hopping models at separate temperature ranges. It was mainly deduced that the presence of trapped water molecules within naturally grown zeolites contributes to the increase of both dielectric constant and conductivity. In addition, milling effect on the structural, morphological, mechanical and thermal properties was investigated respectively through X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis (PSA) as well as a combination of thermogravimetric analysis (TGA) and differential thermal analysis (DTA). XRD confirmed the clinoptilolite phase and monoclinic crystal structure of the prepared samples and suggested a decrease in crystallite size with milling. SEM images manifested a corn flake-like structure of clinoptilolite grains and suggested a decrease in porosity, roughness and particle size under stirring effect. The decrease in overall particle size as a result of the milling process was also confirmed by PSA. Through TGA and DTA, the overall mass and water losses were estimated as a function of temperature, and this along with the morphological observation were correlated with the observed electrical and dielectric properties of the prepared samples. All in all, it was deduced that such naturally grown electroceramics have the potential to be used as natural dielectric capacitors as well as semi-insulator (SI) substrates in integrated circuits of electronic devices.