Study on water vapor corrosion resistance of rare earth monosilicates RE2SiO5 (RE = Lu, Yb, Tm, Er, Ho, Dy, Y, and Sc) from first-principles calculations

Corrosion resistance of rare earth monosilicates (RE 2 SiO 5 , RE=Lu, Yb, Tm, Er, Ho, Dy, Y, and Sc) in water vapor has been studied using the first-principles calculations. The results show that the water vapor corrosion resistance of RE 2 SiO 5 demonstrates the following order: Sc 2 SiO 5 > Dy 2 SiO 5 > Y 2 SiO 5 > Ho 2 SiO 5 > Er 2 SiO 5 > Yb 2 SiO 5 > Tm 2 SiO 5 > Lu 2 SiO 5 . To further improve their water vapor resistance, a doping strategy has been employed for the first time. Two scenarios have been investigated: one is a half mole proportion of substitution of various rare earth elements for Yb in the Yb 2 SiO 5 lattice; the other is a half mole fraction substitution of rare earth elements in RE 2 SiO 5 (RE = Lu, Yb, Er and Y) by scandium. It is unveiled that the water vapor resistance of YbScSiO 5 and YScSiO 5 has been greatly improved in contrast to other rare earth monosilicates. The current study provides guidelines for the selection of environmental barrier coatings with a better water vapor corrosion resistance.