By means of analogy of single side crack of finite size lath, through approximate solution of the quartic equation,two curves of b/R_1 = 1/20 and b/R_1→0 have been found, then the curve of F (a/b, 15/760) drawn by using imerpolation method, final the value of F (5/15, 15/760) of crack size suitable for the degester calculated.
XRD indicates that the sample is wurtzite(hexagonal) structured ZnO with lattice constants of a=3.249 ,c=5.206 and lattice symmetry group(S.G)of P63mc(186). SEM shows that the length,the width and the thickness of the battens are about 20 micrometer,50~300 nanometer and 30 micrometer,respectively.