Abstract
The purpose of this study is the manufacture of SiP2O7 powder, using low-cost material, namely, phosphoric acid and activated metakaolin (AMK).The mineralogical characterization by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) analysis showed that SiP2O7 has a well-crystalline structure. The conductivity and dielectric behavior have been studied over a frequency range from 40 Hz to 5 × 106 Hz and at temperatures ranging from 20 °C to 300 °C. The results indicate that the SiP2O7 synthesized by activated metakaolin have a high ionic electrical conductivity of 2.96 × 10−6 Scm−1 at room temperature, which increases to 8.8 × 10−3 Scm−1 at 300 °C. Furthermore, the powder exhibited a high dielectric constant (120 × 105) and loss factor (350 × 105) at 300 °C, which both decreased with increasing frequency. The imaginary electric modulus (M") showed that the dielectric relaxation time (τ) varies nearly linearly with temperature.
•Pure SiP2O7 was prepared using activated clay as a natural source of silica.•Identification methods are XRD, FTIR, 29Si and 31 P NMR.•The effect of temperatures on the conductivity and dielectric properties is studied.•The SiP2O7 exhibited a high dielectric constant and loss factor at 300 °C