Effect of post-heat-treatment on the structural, spectroscopic and dissolution properties of a highly stable Er3+-doped multi-component phosphate glass

•A highly stable Er3+-doped phosphate glass was synthesized and characterized.•The glass was heat-treated using different temperatures and time intervals.•La, Gd-monazite and AlKP2O7 crystalline phases precipitated at the surface of glass.•A more polymerized glass formed close to the surface crystalline layer.•Some of the Er3+ ions were incorporated in the precipitated crystalline phases.