Table 1: The distance (d) between the (002) lattice plane and the average grain size (D) of the films calculated from XRD pattern.

Temperature FWHM (deg.) 2θ (deg.) d (nm) D (nm)
Blank 0.920 34.354 0.5217 9.038
500 ℃ 0.659 34.457 0.5202 12.621
600 ℃ 0.608 34.477 0.5199 13.681
700 ℃ 0.487 34.477 0.5199 17.080