Fig. 5

Tauc plot of (a) NaSm(WO4)2 [S1/H1/EG1], (b) NaHo(WO4)2 [S2/H2/EG2] and (c) NaPr(WO4)2 [S3/H3/EG3] determined from the Tauc plot.

Tauc plot of (a) NaSm(WO4)2 [S1/H1/EG1], (b) NaHo(WO4)2 [S2/H2/EG2] and (c) NaPr(WO4)2 [S3/H3/EG3] determined from the Tauc plot.