Table 1. Crystallite Size (D) and Lattice Constants (a and c) for the Undoped and Co-, Mn-, and Cu-Doped ZnO Nanostructures.

				lattice parameters
sample	2θ (deg)	d (101) (Å)	D (nm)	a	c
undoped ZnO	36.58	2.454	14.71	3.249	5.206
0.25 at. % Co	36.55	2.455	16.53	3.261	4.962
0.25 at. % Mn	36.45	2.461	21.59	3.263	5.005
0.25 at. % Cu	36.14	2.482	24.61	3.262	5.192