Influence of Rare Earth Cation Size on the Crystal Structure in Rare Earth Silicates, Na2RESiO4(OH) (RE: Sc, Yb) and NaRESiO4 (RE: La, Yb).

Single crystals of Na2ScSiO4(OH) (I) and Na2YbSiO4(OH) (II) are prepared by hydrothermal reaction of a 2:1 molar mixture of Na2SiO3 and Sc2O3 (Yb2O3) in a NaOH based hydroflux (autoclave, 230 °C, 48 h; cooling to 80 °C at a rate of 0.1 °C/min for (I) or quenching to 25 °C).