Fig. 10: Surface aleration and microstructure evolution of the (Sc0.1Lu0.3Yb0.2Y0.3Gd0.1)PO4 after steam corrosion.

SEM images taken at the top surface of the (Sc0.1Lu0.3Yb0.2Y0.3Gd0.1)PO4 sample post vapor corrosion at 1400 °C for 60 h: a a low magnification and b a higher magnification image of corroded region (the inset is a SEM image of pristine surface). SEM images of the cross-section of the coupon post vapor corrosion: c a low magnification and d a high magnification.