Influence of Rare Earth Doping on Microstructure and Luminescence Behaviour of Sodium Sulphate

Table 2

Comparison of lattice parameters and cell volume of pure, Li-doped, and RE³⁺-codoped Na₂SO₄ samples.

Phosphor	𝑎 (Å)		𝑏 (Å)		𝑐 (Å)		𝑉 (Å)^3
	T	M	T	M	T	M	T	M
Na2SO4	5.80	—	12.20	—	7.60	—	538	—
Na2SO4 : Li0.5%	5.86	—	12.32	—	7.66	—	553	—
Na2SO4 : Li0.5%, Eu0.5%, Dy0.2%	10.7	9.51	10.43	15.6	6.08	3.452	679	512
Na2SO4 : Li0.5%, Eu0.5%, Dy0.5%	11.0	9.55	10.47	15.8	6.12	3.481	705	525

T and M correspond to thenardite and mirabilite content of Na₂SO₄.