Synthesis and characterization of [Na.sub.2]O-CaO-Si[O.sub.2] glass-ceramic

The [Na.sub.2]O-CaO-Si[O.sub.2] ternary glass-ceramic with the composition of 49 mass% [Na.sub.2]O, 20 mass% CaO, and 31 mass% Si[O.sub.2] was prepared by the conventional method. The ternary glass-ceramic was characterized using X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The [Na.sub.2]CaSi[O.sub.4] phase, having the cubic crystal system, with the crystallite size of 25.14 nm and lattice parameter of 0.7506 nm was determined from the XRD pattern. The activation energy of the glass-ceramic calculated from the DTA curves was found to be 162.02 kJ [mol.sup.-1]. The Avrami exponent was found to be ~2 indicating a one-dimensional growth process. The mass loss percent from ambient temperature to 1,173 K is less than 1%. The density was calculated to be 2,723 kg [m.sup.-3]. The fine-grained microstructure with the particle sizes less than 1 µm was confirmed by the scanning electron microscope micrograph.