The thermophysical properties of primary phase in lithium germanium phosphate glass

Abstract

The selected lithium germanium-phosphate glass was prepared by a conventional melt-quenching technique. The XRD method was employed to confirm the glass was obtained and to reveal crystalline phases during heat treatment. The dilatometry (DIL), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) were used to determine the characteristic temperatures and enthalpies of crystallization and melting of the crystalline phase. The DTA and DIL were used to obtain the viscosity curves by applying the Vogel-Fulcher-Tammann (VFT) equation

The analysis of the nucleation process of the lithium germanium phosphate glass

“…During the analysis of the phase composition and the crystallization mechanism, of the four-component LAGP glass, XRD analyses revealed that this glass crystallizes polymorphic, which provides the possibility of using a non-isothermal method to study the nucleation process [15]. It is noticed (Fig.…”

“…The high nucleation rates (I), of the four-component glass composition ~ 10 16 m 3 s -1 in the examined temperature range T = 510-565 o C are related to the small values of the kinetic and thermodynamic barrier because the growth process of the crystal phase of glass is determined by phase boundary processes. The melting entropy of the tested glass is ΔS m = 44.08 Jmol -1 K -1 [15]. Based on this value, which is greater than 4R [31,32], the entropy change can be considered as large and the crystal growth process can be described as -growth at the "smooth" boundary by a spiral screw dislocation model.…”