If your synthesized material is amorphous, then XRD is not applicable since it is used to probe inter-planar distances of crystalline materials. But one thing, LDHs are crystalline materials so maybe you did not get the right product.
Tesfay Réda, my question about some no identifier peak, i get the LDH but with some pic maybe oxide so can idenfie this peak by Rigaku PDXL 2 or i must pass by JCPDS file??