“…2,3,11,13,14,[18][19][20][21][22][23][24][25][26][27] Silicates ͑i.e., a mixture of a metal oxide and SiO 2 ͒ have also been widely investigated, with the main focus put on Hf silicates. 2,3,11,13,14,[18][19][20][21][22][23][24][25][26][27] Silicates ͑i.e., a mixture of a metal oxide and SiO 2 ͒ have also been widely investigated, with the main focus put on Hf silicates.…”