Thermogravimetric and temperature-dependent electrical investigations of Pr3+ doped multi-component silicate glasses for microelectronic technology

Abstract

Multi-component silicate glasses doped with 0, 0.5, 1, and 1.5 mol% of praseodymium (Pr3+) were synthesized by the sol–gel method. Thermal analysis of the glasses, evinced a high working temperature of 351 °C and Hruby coefficient, K H = 1.415 in the highly doped system, corroborating the effective role of Pr3+ ions in endowing superior thermal stability to the glass. Broadband dielectric spectroscopy was applied to study the temperature-dependent electrical behavior of the glasses for their suitability as electrodes and solid electrolyte materials in batteries. A high dielectric constant of 4797 was evidenced at 1 kHz when recorded at 473 K. The AC conductivity of the glass doped with 1 mol% was observed to be the highest with 94.8 × 10−5 S cm−1 at 10 MHz and 473 K. Jonscher’s power law exponent decreased with temperature, attributing the conducting mechanism to the Correlated Barrier Hopping (CBH) model. The Nyquist impedance spectra demonstrated a depressed semicircle with a spur at the low-frequency end, validating the non-Debye relaxation in the glasses. The equivalent circuitry of the plot predicted parallel combinations of resistor and constant phase elements which reflects a Warburg diffusion and capacitive approach. Bode’s phasor diagram confirmed the capacitive nature by a phase angle of −90° in all the glasses. While a uniform increase in dielectric constant and conductivity was observed up to 1 mol% of Pr3+, a sharp decline in the electrical phenomenon was observed with 1.5 mol% of Pr3+, due to the possible blockade of the hopping of charge carriers by the largely quantified dopant ions. Extracting a high dielectric constant, and ionic conductivity at high frequencies, with an optimal dopant concentration of 1 mol% Pr3+, the composite glasses could be considered for their potential use in integrated microcomponent storage devices as cathode and solid electrolyte materials.