“…Alahakoon et al obtained almost a single phase ZrSiO 4 at 1400 °C by using 5% iron as a dopant with no detection of iron oxide as a separate phase, and this means that Fe has entered the crystal lattice of ZrSiO 4 . 49 K.-R. Pyon and B.-H. Lee investigated the effect of iron as a dopant by varying its concentration from 5−30% and concluded that all the investigated compositions resulted in the formation of mixture of multiple phases, namely, α-Fe 2 O 3 , ZrSiO 4 , t-ZrO 2 , m-ZrO 2 , and c-SiO 2 at 1300 °C. 50 Herrera et al obtained solid solution of iron doped ZrSiO 4 at 1100 °C, and they also demonstrated that Fe 3+ has occupied the tetrahedral lattice of ZrSiO 4 by replacing Si 4+ ions.…”