Study on water vapor corrosion resistance of rare earth monosilicates RE(2)SiO(5) (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.