Preparation and studies of some thermal, mechanical and optical properties of 𝑥Al2O3(1 �?? �?)NaPO3 glass system

[摘要] Sodium aluminophosphate glasses having compositions of 𝑥Al₂O₃(1 â€�?? ð‘�?)NaPO₃ (ð‘�? = 0.05â€�??0.2) were prepared using conventional melt-quench technique. Density, glass transition temperature, microhardness (MH), thermal expansion coefficient (TEC) and transmission characteristics were measured as a function of alumina content for different samples. They were found to depend on O/P ratio with pronounced changes taking place for O/P ratio â‰�? 3.5. Density, glass transition temperature and microhardness were found to increase up to 15 mol% of alumina and then they showed a decreasing trend. Thermal expansion coefficient decreased continuously with alumina content. Optical gaps for different glass samples as measured from transmission characteristics were found to be in the range 3.13â€�??3.51 eV. It initially decreased with alumina content up to 15 mol% and then increased. The behaviour was explained on the basis of change in the average aluminum coordination number from six Al(6) to four Al(4) (i.e. Al(OP)₆/Al(OP)₄ ratio) along with the changes in polyhedra linkages in the glass network due to change in O/P ratio.

[学科分类] 材料工程

[关键词] Phosphate glass;thermal expansion coefficient;microhardness;optical gap.