It is interesting to note that these peaks a all from atomic planes perpendicular to the c-axis of the crystal structure.
As the temperature increases to 150 , the intensities of the new peaks surge drastically -a sign of the growth of the grains- while those of other peaks drop significantly.
These extraordinary changes in the XRD results suggest that very drastic materials processes occurred in the films during the annealing:
(1) Upon annealing a 100 , emerged are some new grains with their c-axis oriented the normal direction:
(2) The grains grew very large to become dominant grains further annealing at higher temper- atures (150 and 200 oC).