In this work we accomplished a study about the influence of doping Mn+2, Mg+2 and Cu+2 in the crystal structures of crystals of nickel sulfate hexahydrate (NSH) and L Asparagine Monohydrate (LAM). The introduction of dopants in a crystal lattice must change its physical properties or growth habit. These changes must promote the technological applications of these crystals in many areas like medicine, agriculture, optics and electronics. The NSH crystals were grown by the slow evaporation method of the solvent and doped with ions of Mn+2 and Mg+2, resulting in crystals of good quality. We measures method of X-ray diffraction of the pure crystals and polycrystalline doped and from the results obtained we refinements, using the method of Rietiveld where was observed that the same crystal structure doped showed the same tetragonal and space
group that the pure crystal, having a little change in their lattice parameters and volume of its unit cells. We observed that the introduction of dopants caused changes in the lengths of the links and the angles between the nickel and oxygen atoms, this may explain why the temperature of dehydration crystals NSH:Mn and NSH:Mg is bigger than that of pure NSH. We use the X-ray Diffraction Multiple technique with synchrotron radiation in differents energies on the workstation XRD1, of the National Synchrotron Light Laboratory (LNLS)
in order to identify possible changes in the structures of doped crystals of nickel sulphate and L Asparagine. The Renninger diagrams show changes in the intensity, profile and position of the secondary peaks of doped crystals caused by the introduction of dopants. The crystals were grown L Asparagine monohydrate by the method of slow solvent evaporation, and doped with ions of Cu+2. The diffraction measurements showed that the doped crystal has the same orthorhombic structure that the pure crystal. Our results indicate that the incorporation mechanisms of the Cu+2 ions in the crystal lattice of Asparagine Monohydrate L occur in interstitial form. Changes were detected in intensity as well as in the positions and profile diagrams Renninger secondary peaks in the crystal doped.
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