Structural and Textural Modifications of Ternary Phosphate Glasses by Thermal Treatment

Phosphate‐based glasses of composition x Na ₂ O −(45+(10− x )) CaO −45 P ₂ O ₅ with different Na ₂ O , CaO ( x = 1, 5, 10, 15, and 20 mol%), and invariable P ₂ O ₅ (45 mol%) contents were prepared using the rapid melt quench technique. The obtained thermal data from differential thermal analysis revealed a decline in glass transition ( T _g ) and crystallization ( T _c ) temperatures of glasses against the compositional changes. The inclusion of Na ₂ O at the cost of CaO in the glass network led to a reduction in its thermal stability. The thermal treatment carried out on glasses helped to derive their glass‐ceramic counterparts. The amorphous and crystalline features of samples were characterized using X ‐ray diffraction patterns. The crystalline species that emerged out of the calcium phosphate phases confirmed the dominance of Q ¹ and Q ² structural distributions in the investigated glass‐ceramics. The obtained scanning electron micrographs and atomic force microscopic images confirmed the surface crystallization and textural modification of the samples after thermal treatment. The N ₂ ‐adsorption–desorption studies explored the reduction of porous structures due to thermal treatment on the melt‐driven glass surface. The measured elastic moduli and V icker's hardness values of the glasses showed an increase after thermal treatment, which were reduced against the inclusion of alkali content in both glass and glass‐ceramics.