1Magnetism and Superconducting Research Laboratory, Department of Physics, Faculty of Science, University of Birjand, Birjand, Iran.
2Department of physics, Ferdowsi University of Mashhad
3Department of Material Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
The present study deals with the experimental and theoretical approaches of LaNi5 hydrogen storage alloy. The structural, morphological and hydrogenation characterization of this sample which is synthesized by the arc melting technique were carried out by X-ray diffraction, scanning electron microscopy and a homemade Sievert's type apparatus, respectively. The results showed that after several hydrogenation/dehydrogenation cycles, disproportionation occur in LaNi5. The hydriding kinetic measurements under different applied pressure show that the hydrogen storage capacity (Cwt.%) increases with pressure. However, kinetic analysis at different temperatures under constant initial pressure, which is fitted to two models such as Jander diffusion model and Johnson-Mehl-Avarmi, revealed that Cwt.% and hydriding reaction rate are decreased and increased by increasing of temperature, respectively. The theoretical study using full potential linearized augmented plane wave plus local orbitals method was also performed to investigate the structural, energetic and electronic properties of LaNi5 and its saturated hydride (LaNi5H7). From the two possible space groups for LaNi5H7, P63mc was found as the most favorable one. A volume expansion of ~%26 was found for its hydride. Other calculated results including the equilibrium atomic positions, bulk modulus and the enthalpy of formation were in good agreement with other theoretical and experimental results. The band structure calculations showed that the valence bands were mainly derived from Ni-3d states, and the bandwidth of the occupied Ni-3d bands in hydride phase was narrower than that of the parent compound due to the filling of Ni-3d bands as a result of hydrogen absorption and volume expansion.
 Hirscher M., Handbook of Hydrogen Storage: New Materials for Future Energy Storage, Wiley-VCH. Press, 2010.
 Broom D. P., Hydrogen Storage Materials, Green Energy and Technology, Springer-Verlag, 2011.
 Alefeld G. and Völkl J., Hydrogen in Metals II, Topics in Applied Physics, Springer-Verlag, 1978.
 Zhu K. G., Shi J. Z. and Zhang L.D., “Effect of temperature on electrical resistivity of a hydrogenated LaNi5 thin film", Chin. Phys., 1998, 7: 504
 Lin S. J. and Zheng H. P., "Electronic structure of the surface of LaNi5 crystal", Acta Phys. Sin., 2005, 10: 4680
 Rozdzynska-Kielbik B., Iwasieczko W., Drulis H., Pavlyuk V.V. and Bala, H., "Hydrogenation equilibria characteristics of LaNi5-xZnx intermetallics", ", J. Alloys Comp., 2000, 298: 237
 Zareii S. M. and Sarhaddi R., "Structural, electronic properties and heat of formation of Mg2FeH6 complex hydride: an ab initio study", Phys. Scr., 2012, 86: 015701
 Mungole M. N., Balasubramaniam R. and Rai K. N., "Magnetization behavior of hydrogen storage MmNi5 intermetallics with Al, Mn and Sn substitutions", Int. J. Hydrogen Energy, 1997, 22: 679
 Biris A., Bucur R.V., Ghete P., Indrea E. and Lupu D., "The solubility of deuterium in LaNi5", J. Less-Common Met., 1976,49: 477
 Tatsumi K., Tanaka I., Inui H., Tanaka K., Yamaguchi M. and Adachi H., "Atomic structures and energetics of LaNi5-H solid solution and hydrides", Phys. Rev. B, 2001,64: 184105.
 Hector Jr L.G., Herbst J. F. and Capehart T. W., "Electronic structure calculations for LaNi5 and LaNi5H7: energetics and elastic properties", J. Alloys Comp., 2003, 353: 74
 Lartigue C., Le Bail A. and Percheron-Guegan A., "A new study of the structure of LaNi5D6.7 using a modified Rietveld method for the refinement of neutron powder diffraction data", J. Less-Common Met., 1987, 129: 65
 Al Alam A. F., Matar S. F., Nakhl M. and Ouaïni N., "Investigation of changes in crystal and electronic structures by hydrogen within LaNi5 from first-principles", Solid State Sciences, 2009, 11: 1098
 Blaha P., Schwarz K., Madsen G. K. H., Kvanicka D. and Luitz J., An Augmented Plane Wave Plus Local Orbitals Program for Calculating Crystal Properties, Vienna University of Technology, 2001.
 Perdew J. P., Burke K. and Ernzerhof M., "Generalized Gradient Approximation Made Simple", Phys. Rev. Lett., 1996, 77: 3865
 Blochl P. E., Jepsen O. and Andersen O. K., "Improved tetrahedron method for Brillouin-zone integrations", Phys. Rev. B, 2004,49: 16223
 Nakamura Y., Sato K., Fujitani S., Nishio K., Oguro K. and Uehara I., "Lattice expanding behavior and degradation of LaNi5-based alloys", J. Alloys Comp., 1998, 267: 205
 Srivastava S. and Upadhyaya R. K., "Investigations of AB5-type hydrogen storage materials with enhanced hydrogen storage capacity", Int. J. Hydrogen Energy, 2001, 36: 7114
 Ahn H. J. and Lee J. Y., "Intrinsic degradation of LaNi5 by the temperature induced hydrogen absorption-desorption cycling", Int. J. Hydrogen Energy, 1991, 16: 93
 Tian X., Liu X-d., Xu J., Feng H-w., Chi B., Huang L-H and Yan S-F., "Microstructures and electrochemical characteristics of Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3 hydrogen storage alloys prepared by mechanical alloying", Int. J. Hydrogen Energy, 2009, 34: 2295
 Cerny R., Joubert J.-M., Latroche M., Percheron-Guegan A. and Yvon K.; "Anisotropic diffraction peak broadening and dislocation substructure in hydrogen-cycled LaNi5 and substitutional derivatives", J. Appl. Cryst., 2000, 33: 997
 Srivastava S. and Srivastava O. N., "Investigations of synthesis and characterization of MmNi4.3Al0.3Mn0.4 and MmNi4.0Al0.3Mn0.4Si0.3, hydrogen storage materials through thermal and spin melting processes", Int. J. Hydrogen Energy, 1998, 23: 7
 Li S.L., Chen W., Chen D.M. and Yang K., “Effect of long-term hydrogen absorption/desorption cycling on hydrogen storage properties of MmNi3.55Co0.75Mn0.4Al0.3”, J. Alloys Compd., 2009, 474:164
 Li S.L., Chen W., Luo G., Han X.B., Chen D.M., Yang K. and Chen W.P., “Effect of hydrogen absorption/desorption cycling on hydrogen storage properties of a LaNi3.8Al1.0Mn0.2 alloy”, Int. J. Hydrogen Energy, 2012, 37:3268
 Johnson D. G. and Pangborn J. B., ibid., 1980, 73: 127
 Zhang T. B., Wang X. F., Hu R., Li J. S., Yang X. W., Xue X. Y. and Fu H. Z., "Hydrogen absorption properties of Zr(V1-xFex)2 intermetallic compounds", Int. J. Hydrogen Energy, 2012, 37: 2328
 Ivey D. G. and Northwood D. O., "Storing energy in metal hydrides: a review of the physical metallurgy", J. Mater. Sci., 1983, 18: 321
 Haberman Z., Bloch J., Mintz M. H. and I Jacob I., "Kinetics of hydride formation in massive LaAl0.25Ni4.75 samples", J. Alloys Compd., 1997, 253-254: 556
 Muthukumar P., Satheesh A., Linde M., Mertz R. and Groll M., "Studies on hydriding kinetics of some La-based metal hydride alloys", Int. J. Hydrogen Energy, 2009, 34: 7253
 Ming L., Lavendar E., Goudy A.J., “The hydriding and dehydriding kinetics of some RCo5 alloys”, Int. J. Hydrogen Energy, 1997, 22: 63.
 Chou K. C., Xu K. D., "A new model for hydriding and dehydriding reactions in intermetallics", Intermetallics, 2007, 15: 767
 Zhang X., Li Q. and Chou K. C., " Kinetics of hydrogen absorption in the solid solution region for Laves phase Ho1-xMmxCo2 (x = 0, 0.2 and 0.4) alloys", Intermetallics, 2008, 16:1258
 Jander W., Reaktionen im festen Zustande bei höheren Temperaturen. Reaktionsgeschwindigkeiten endotherm verlaufender Umsetzungen, Z. Anorg. Allg. Chem., 1927, 163: 1
 Johnson W. A. and Mehl R. F., "Reaction kinetics in processes of nucleation and growth", Trans. Am. Inst. Min. Metall. Eng., 1939, 135: 416
 Murnaghan F. D., "The Compressibility of Media under Extreme Pressures"; Proc. Natl. Acad. Sci. USA, 1944, 30: 244
 Feynman R. P., "Forces in Molecules", Phys. Rev., 1939, 56: 340
 Nakamura H., Nguyen-Manh D. and Pettifor D.G., "Electronic structure and energetics of LaNi5, α-La2Ni10H and β-La2Ni10H14", J. Alloys Comp., 1998, 281: 81
 Bereznitsky M., Ode A., Hightower J. E., Yeheskel O., Jacob I. and Leisure R. G., "Elastic moduli of polycrystalline LaAlxNi5−x", J. Appl. Phys. , 2002, 91:5010
 Brouha M. and Buschow K. H. J., "Magnetic properties of LaCo5xNi5-5x", J. Phys. F: Metal Phys., 1975, 5: 543
 Tanaka K., Okazaki S., Ichitsubo T., Yamamoto T., Inui H., Yamguchi M. and Koiwa M., "Evaluation of elastic strain energy associated with the formation of hydride precipitates in LaNi5", Intermetallics, 2000, 8: 613
 Bouhadda Y., Rabehi A., Boudouma Y., Fenineche N., Drablia S. and Meradji H., "Hydrogen solid storage: First-principles study of ZrNiH3", Int. J. Hydrogen Energy, 2009, 34: 4997
 Hubbard W. N., Rawlins P. L., Connick P. A., Stedwell Jr R. E. and O'Hare P. A. G., "The standard enthalpy of formation of LaNi5 The enthalpies of hydriding of LaNi5−xAlx", The Journal of Chemical Thermodynamics, 1983,15: 785
 Murray J. J., Post M. L. and Taylor J. B., "The thermodynamics of the LaNi5-H2 system by differential heat flow calorimetry II: The α and β single-phase regions", J. Less-Common Met., 1981, 80: 211
 Wallace W.E. and Pourarian. F., "Photoemission Studies of LaNi5-xCux Alloys and Relation to Hydride Formation", J. Phys. Chem., 1982, 86: 4958
 Knyazev Y. V., Lukoyanov A. V., Kuzmin Y. I. and Kuchin A. G., "Effect of Cu-doping on the electronic structure and optical properties of LaNi5", J. Alloys Comp., 2011, 509: 5238
 Fuggle J. C., Hillebrecht F. U., Zeller R., Zolnierek Z., Bennett P. A. and Freiburg Ch., "Electronic structure of Ni and Pd alloys. I. X-ray photoelectron spectroscopy of the valence bands", Phys. Rev. B, 1982, 27: 2145
 Weaver J. H., Franciosi A., Wallace W. E.and Smith H. K., "Electronic structure and surface oxidation of LaNi5, Er6Mn23, and related systems", J. Appl. Phys., 1980, 51: 5847