Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-28T09:24:13.244Z Has data issue: false hasContentIssue false

Ab initio study of mechanical stability, thermodynamic and elastic properties of Rh, RhH, and RhH2 under high temperature and pressure

Published online by Cambridge University Press:  15 July 2014

Guobing Pan
Affiliation:
School of Civil Engineering & Architecture, Chongqing Jiaotong University, Chongqing 400074, China
Chenghua Hu*
Affiliation:
Chongqing Jiaotong University, Chongqing 400074, China
P. Zhou
Affiliation:
Chongqing Jiaotong University, Chongqing 400074, China
Feng Wang
Affiliation:
Chongqing Jiaotong University, Chongqing 400074, China
Zhou Zheng
Affiliation:
Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
Bo Liang*
Affiliation:
School of Civil Engineering & Architecture, Chongqing Jiaotong University, Chongqing 400074, China
*
a)Address all correspondence to these authors. e-mail: [email protected]
Get access

Abstract

In this work, mechanical stability, thermodynamic and elastic properties of rhodium (Rh), rhodium monohydride (RhH), and the newly discovered rhodium dihydride (RhH2) under high temperature and pressure are studied by ab initio method together with quasiharmonic Debye model. Mechanical stability test indicates that RhH2 is no longer mechanically stable when pressure is higher than 22.7 GPa, which is quite less than the dynamically stable pressure (90 GPa). The heat capacity at constant volume (Cv) of Rh, RhH, or RhH2 increases proportional to T3 at low temperature, and tends to Dulong–Petit limit (about 241.67, 478.47, and 706.15 J/(kg·K), respectively). The thermal expansion coefficient (α) of Rh, RhH, and RhH2 increases acutely when temperature is not more than 300 K. And then, the increase of α slows down. The α reduces with pressure transiently. H atom's entering in fcc-Rh lattice would greatly change the electron density distribution, which would cause obvious difference in thermodynamic and elastic properties between Rh, RhH, and RhH2.

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Grochala, W. and Edwards, P.P.: Thermal decomposition of the non-interstitial hydrides for the storage and production of hydrogen. Chem. Rev. 104, 12831315 (2004).Google Scholar
Somayazulu, M., Dera, P., Goncharov, A.F., Gramsch, S.A., Liermann, P., Yang, W., Liu, Z., Mao, H., and Hemley, R.J.: Pressure-induced bonding and compound formation in xenon hydrogen solids. Nat. Chem. 2, 5053 (2010).Google Scholar
Baettig, P. and Zurek, E.: Pressure-stabilized sodium polyhydrides: NaHn (n>1). Phys. Rev. Lett. 106, 237002 (2011).CrossRefGoogle ScholarPubMed
Markopoulos, G., Kroll, P., and Hoffmann, R.: Compressing the most hydrogen-rich inorganic ion. J. Am. Chem. Soc. 132, 748755 (2010).Google Scholar
Fukai, Y.: The Metal-Hydrogen System: Basic Bulk Properties (Springer, Berlin, 2005); p. 497.Google Scholar
Mitsui, T., Rose, M.K., Fomin, E., Ogletree, D.F., and Salmeron, M.: Dissociative hydrogen adsorption on palladium requires aggregates of three or more vacancies. Nature 422, 705707 (2003).Google Scholar
Lopez, N., Łodziana, Z., Illas, F., and Salmeron, M.: When Langmuir is too simple: H2 dissociation on Pd (111) at high coverage. Phys. Rev. Lett. 93, 146103 (2004).Google Scholar
Antonov, V.E., Belash, I.T., Malyshev, V.Y., and Ponyatovsky, E.G.: The solubility of hydrogen in the platinum metals under high pressure. Platinum Met. Rev. 28, 158163 (1984).Google Scholar
Li, B., Ding, Y., Kim, D.Y., Ahuja, R., Zou, G., and Mao, H.K.: Rhodium dihydride (RhH2) with high volumetric hydrogen density. PNAS 108, 1861818621 (2011).Google Scholar
Hohenberg, P. and Kohn, W.: Inhomogeneous electron gas. Phys. Rev. 136, B864B871 (1964).Google Scholar
Kohn, W. and Sham, L.J.: Self-consistent equations including exchange and correlation effects. Phys. Rev. 140, A1133A1138 (1965).Google Scholar
Becke, A.D.: Density-functional thermochemistry. III. The role of exact exchange. J. Chem. Phys. 98, 5648 (1993).Google Scholar
Lee, C., Yang, W., and Parr, R.G.: Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 37(2), 785789 (1988).CrossRefGoogle ScholarPubMed
Stephens, P.J., Devlin, F.J., Chabalowski, C.F., and Frisch, M.J.: Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields. J. Phys. Chem. 98(45), 1162311627 (1994).Google Scholar
Blanco, M., Francisco, E., and Luana, V.: GIBBS: Isothermal-isobaric thermodynamics of solids from energy curves using a quasi-harmonic Debye model. Comput. Phys. Commun. 158(1), 5772 (2004).Google Scholar
Otero-de-la-Roza, A., Abbasi-Pérez, D., and Luaña, V.: Gibbs2: A new version of the quasi harmonic model code. II. Models for solid-state thermodynamics, features and implementation. Comput. Phys. Commun. 182(10), 22322248 (2011).Google Scholar
Perdew, J.P., Burke, K., and Ernzerhof, M.: Generalized gradient approximation made simple. Phys. Rev. Lett. 77(18), 38653868 (1996).Google Scholar
Fast, L., Wills, J.M., Johansson, B., and Eriksson, O.: Elastic constants of hexagonal transition metals: Theory. Phys. Rev. B 51, 17431 (1995).Google Scholar
Sin’ko, G.V. and Smirnow, N.A.: Ab initio calculations of elastic constants and thermodynamic properties of bcc, fcc, and hcp Al crystals under pressure. J. Phys.: Condens. Matter 14, 6989 (2002).Google Scholar
Hull, A.W. and Davey, W.P.: Graphical determination of hexagonal and tetragonal crystal structures from x-ray data. Phys. Rev. 17, 549570 (1921).Google Scholar
Singh, H.P.: Determination of thermal expansion of germanium, rhodium and iridium by x-rays. Acta Crystallogr., A 24, 469471 (1968).CrossRefGoogle Scholar
Somenkov, V.A., Glazkov, V.P., Irodova, A.V., and Shilstein, S.S.: Crystal structure and volume effects in the hydrides of d metals. J. Less Common Met. 129, 171180 (1987).Google Scholar
Einstein, A.: Die plancksche theorie der strahlung und die theorie der spezifischen wärme. Ann. Phys. 327, 180190 (1906).Google Scholar
Nernst, W., Lindeman, F., and Elektrochem, Z.: Specific heat and quantum therory. Z. Elektrochem. Angew. Phys. Chem. 17, 817827 (1911).Google Scholar
Debye, P.: Zur theorie der spezifischen wärmen. Ann. Phys. 39, 789839 (1912).Google Scholar
Petit, A.T. and Dulong, P.L.: Recherches sur quelques points importants de la chaleur. Ann. Chim. Phys. 10, 395413 (1819).Google Scholar