Low Pressure-induced Phase Transition Study of α-AlH3 and its Hydrogen Storage Evaluation for Energy Applications via Electronic, Structural, Thermodynamic and Optical Analysis
Keywords:
Electronic analysis, Hydrogen storage, Phase transition, Optical propertiesAbstract
Metal hydrides are currently one of the most investigated materials for energy storage applications. In this study, the structural, electronic, and optical properties of α-AlH3 have been investigated from density functional theory (DFT) calculations. This work is aimed at studying the low pressure-induced phase transition of α-AlH3 hydride material in the range of 1 - 8 GPa pressure. Self-consistent field (scf) calculations based on the DFT approach were performed using exchange-correlation functionals from generalized gradient approximation (GGA). Structural properties such as lattice constant (4.6973 Å), formation enthalpy, bond distance of Al – H, Al – Al, and H – H, are observed to be consistent with experiments. The electronic density of state (DOS) revealed the band gap as 2.16 eV. Analysis of the gravimetric storage and volumetric storage capacities, as well as the desorption temperature of α-AlH3 have been performed. The electronic band structure analysis from increased applied pressures shows that the compound is an indirect band gap semiconductor, and retains this nature via the entire applied pressure. Also, a monoclinic distortion of the compound due to the octahedral [AlH6] tilting of the unit cell is sustained within the pressure range in this study, and this confirms reported experiments. However, the applied pressure evaluation of the electronic band structure revealed a transition state at 3 GPa. This observation was further confirmed by structural analysis owing to the formation of bonds, with no discontinuity found in the structure at increased pressures. Meanwhile, thermodynamic analysis depicts a transition state at 3 GPa with the free energy observed to be − 0.04 Ry, entropy S ≈ 2.1 x 10–4 Ry/K, and heat capacity CV is 1.457 x 10–4 Ry/K at Dulong–Petti limit. The negative free energy verifies the thermodynamic stability of the hydride. Accordingly, the optical study showed an abrupt frequency discontinuity in the spectra of electron energy loss (EEL) function at exactly 3 GPa. The EEL function profile reveals the hydride as a promising photo-absorber at energies below 33 eV.
References
Aguayo, A. & Singh, D. J. (2004). Electronic structure of the complex hydride NaAlH4. Phys. Rev. B 69, 155103.
Ahmed, B., Tahir, M.B., Li, A. & Sagir, M. (2024). First principles screening of structural, electronic, optical and elastic properties of Cu-based hydrides-perovskites XCuH3 (X= Ca and Sr) for hydrogen storage applications. Int. J. Hydrogen Energy, 54, 1001–1007.
Ain, Q., Naeem, H.T., Ali, M., Munir, J., Bibi, Z., Ghaithan, H.M., Ahmed, A.A.A. & Qaid, S.M.H. (2024). A precise prediction of structure stability and hydrogen storage capability of KCdH3 perovskite hydride using density functional theory calculations, J. Energy Storage, 100: 113734
Aliabad, H. A. R. & Yalcin, B.G., (2017). Optoelectronic and thermoelectric response of of band gap from direct to indirect. J. Mater. Sci.: Mater. Electron., https://org.doi/10.1007/s10854-017-7368-6
Aliabad, H.A.R. & Chahkandi, M. (2018). Theoretical study of crystalline network and optoelectronic properties of erlotinib hydrochloride molecule: non-covalent interactions consideration. Chem. Pap. 73, 737–746.
Baranowski, B. & Tkacz, M. (1983). The equilibrium between solid aluminium hydride and gaseous hydrogen. Zeitschrift für Physikalische Chemie, 135 (135), 27 – 38.
Baranowski, B., Hochheimer, H.D., Strossner, K., Honle, W. (1985). High pressure x-ray investigation of AlH3 and Al at room temperature. J. Less-Common Met., 113, 341–347.
Baroni, S., Giannozzi, P., Isaev, E. (2010). Density-functional perturbation theory for quasi-harmonic calculations, Rev. Mineral. Geochem. 71 (1), 39–57.
Becke, A.D., (1988). Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A. 38 (6): 3098–3100.
Becke, A.D. (2014). Perspective: Fifty years of density-functional theory in chemical physics. J. Chem. Phys. 140 (18): A301.
Bencheikh, M. & Farh, L.E. (2024). Modeling and simulation of the structural, and optoelectronic properties of aluminum trihydride (β-AlH3) for hydrogen storage, Intl. J. Hydrogen Energy, 94, 223–231.
Brower, F.M., Matzek, N.E., Reigler, P. F., Rinn, H. W., Roberts, C. B., Schmidt, D. L., Snover, J. A., Terada, K. (1976). "Preparation and properties of aluminum hydride". 98. J. Am. Chem. Soc.: 2450–2454.
Candan, A. & Akbudak, S. (2025). First-principles calculations on the physical properties of Zr-based perovskites LiZrH3 and KZrH3 for potential hydrogen storage applications, Intl. J. Hydrogen Energy 129, 199–210.
Ciezak-Jenkins, J. A. (2011). Low-pressure Structural Modification of Aluminium Hydride. Weapons and Materials Research Directorate, ARL (Army Research Laboratory)., Aberdeen Proving Ground, MD 21005-5069. ARL-TR-5463, 1 – 14.
Drozd, V., Garimella, S., Saxena, S., Chen, J. & Palasyuk, T. (2012). High-Pressure Raman and X-ray Diffraction Study of β- and γ-Polymorphs of Aluminum Hydride. J. Phys. Chem. C, 116, 3808 − 3816.
Ekong, S.A, Fuwape, I.A. & Odo, E.A. (2014b). Ab initio study of the electronic structure of silicon quantum dots. J. Nig. Asso. Math. Phys., 26, 177 – 186.
Ekong, S.A. & Oyegoke, D.A. (2016). QMC calculations of total energy and bond length of some polyatomic organic molecules, Intl. Lett. Chem. Phys. Astron. 64, 63 – 68.
Ekong, S.A., Ebomwonyi, O. & Idiodi, J.O.A. (2014a). Closed-shell ground state energy calculations of the first-row diatomic molecules using quantum Monte Carlo casino - code, J. Nig. Assoc. Math. Phys., 28 (1), 317 – 326.
Ekong, S.A., Oloye, M.T. & Oyegoke, D. A. (2015). Ground-state energy calculation of helium atom using quantum Monte Carlo casino-code, Adv. Phys. Theo. Appl. 46 (1): 1 – 6.
Ekwere, E.J., Emah, J.B. & Ekong, S. A. (2024). Structural, Electronic, Thermophysical and Optical Investigation of Tetragonal (C11b – CrSi2) Material: A Theoretical Analysis, Res. J. Sci. Techn., 4(4): 23 – 38.
Giannozzi, P., Andreussi, O., Brumme, T., Bunau, O., Nardelli, M.B., Calandra, M., Car, R., Cavazzoni,C., Ceresoli, D., Cococcioni, M., Colonna, N., Carnimeo, I., Corso, A. D., Gironcoli, S. de, Delugas, P., DiStasio Jr, R.A., Ferretti, A., Floris, A., Fratesi, G., Fugallo, G., Gebauer, R., Gerstmann, U., Giustino, F., Gorni, T., Jia, J., Kawamura, M., Ko, H-Y., Kokalj, A., Küçükbenli, E., Lazzeri, M., Marsili, M., Marzari, N., Mauri, F., Nguyen, N.L., Nguyen, H-V., Roza, A. O. d-l, Paulatto, L., Poncé, S., Rocca, D., Sabatini, R., Santra, B., Schlipf, M., Seitsonen, A.P., Smogunov, A., Timrov, I., Thonhauser, T., Umari, P., Vast, N., Wu, X., Baroni, S. (2017). Advanced capabilities for materials modelling with QUANTUM ESPRESSO, J. Phys.: Condens. Matter 29 (46), 465901.
Giannozzi, P., Baroni, S., Bonini, N., Calandra, M., Car, R., Cavazzoni, C., Ceresoli, D., Chiarotti, G.L., Cococcioni, M., Dabo, I., Dal Corso, A., Fabris, S., Fratesi, G., de Gironcoli, S., Gebauer, R., Gerstmann, U., Gougoussis, C., Kokalj, A., Lazzeri, M., Martin-Samos, L., Marzari, N., Mauri, F., Mazzarello, R., Paolini, S., Pasquarello, A., Paulatto, L., Sbraccia, C., Scandolo, S., Sclauzero, G., Seitsonen, A.P., Smogunov, A., Umari, P. & Wentzcovitch, R. M. (2009). QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys.: Condensed Matter 21(39), 395502 – 395521.
Goedecker, S., & Teter, M. (1996). Separable dual-space Gaussian pseudopotentials. Physical Review B - Condensed Matter and Materials Physics, 54(3), 1703–1710.
Goncharenko, I.N., Eremets, M.I., Hanfland, M., Tse, J.S., Amboage, M., Yao, Y. & Trojan, I.A. (2008). Pressure-Induced Hydrogen-Dominant Metallic State in Aluminium Hydride. Phys. Rev. Lett. (PRL) 100, 045504: 1 – 4.
Goncharenko, I.N., Glazkov, V.P., Irodova, A.V. & Somenkov, V.A. (1991). Neutron diffraction study of crystal structure and equation of state AlD3 up to the pressure of 7.2 GPa, Physica B: Conden. Matt., 174, 117 – 120.
Graetz, J. & Reilly, J. J. (2006). Thermodynamics of the α, β and γ polymorphs of AlH3. J. Alloys Compd., 424, 262 – 265.
Graetz, J., Chaudhuri, S., Lee, Y., Vogt, T., Muckerman, J.T. & Reilly, J.J. (2006). Pressure-induced structural and electronic changes in α-AlH3. Phys. Rev. B, 74, 214114:1 – 214114:7.
Graetz, J., Chaudhuri, S., Wegrzyn, J., Celebi, Y., Johnson, J.R., Zhou, W. & Reilly, J.J. (2007). J. Phys. Chem. C, 111, 19148 – 19152.
Graetz, J., Reilly, J.J., Yartys, V.A., Maehlen J.P., Bulychev, B.M., Antonov, V.E., Tarasov, B.P. & Gabis, I.E. (2011). Aluminum hydride as a hydrogen and energy storage material: Past, present and future. J. Alloys Comp. 509S, S517 – S528.
Gregory, E. E., Ekong, S. A. & Emah, J. B. (2024). Ab-initio Assessment of the Electronic, Mechanical, Thermal, Optical and Phonon Properties of B3-AlAs, Res. J. Sci. Techn., 4 (3), 69 – 93.
Grew, K.N., Brownlee, Z.B., Shukla, K.C. & Chu, D. (2012). Assessment of Alane as a hydrogen storage media for portable fuel cell power sources. J. Power Sources. 217, 417–430.
Hartwigsen, C., Goedecker, S., & Hutter, J. (1998). Relativistic separable dual-space Gaussian pseudopotentials from H to Rn C. Physical Review B, 58(7), 3641–3662.
Hosen, A., Dahliah, D., Mohammad, N.F.A., Mousa, A.A., & Abu-Jafar, M.S. (2025). A computational study on the comparative analysis of tetragonal complex metal hydride Q2FeH5 (Q = Mg, Ca, Sr) for hydrogen storage applications, Intl. J. Hydrogen Energy, 102, 348 – 359. https://doi.org/-10.1016/j.ijhydene.2025.01.042
Humphries, T. D., Munroe, K. T., Decken, A. & McGrady, G.S. (2013). Lewis base complexes of AlH3: Prediction of preferred structure and stoichiometry. RSC: Dalton Transaction, 42, 6965.
Jolayemi, O. R. & Ekong, S. A. (2020). Electronic, structural, magnetic and mechanical properties of Mg1-xSrxN rocksalt from first-principles, Tran. Nig. Asso. Math. Phys. 13, 39 – 44.
Karazhanov, S. Z., Ravindran, P., Vajeeston, P., & Ulyashin, A.G. (2007). Hydride electronics, Phys. Status Solidi (a) 204 (10) 3538–3544.
Karazhanov, S. Z., Ulyashin, A.G., Ravindran, P., & Vajeeston, P. (2008). Semiconducting hydrides. EPL 82, 72006: 1–5.
Ke, X., Kuwabara, A. & Tanaka, I. (2005). Cubic and orthorhombic structures of aluminum hydride AlH3 predicted by a first-principles study, Phys. Rev. B 71, 184107: 1 – 7.
Kohn, W. & Sham, L.J. (1965). Self-consistent equations including exchange and correlation effects, Phys. Rev., 140 (4A): A1133–A1138.
Malica, C. & Corso. A.D. (2020). Quasi-harmonic temperature dependent elastic constants: applications to silicon, aluminum, and silver. J. Phys.: Condens. Matt., 32 (31), 315902.
Masood, M.K., Chaoui, K., Khan, W., Bahajjaj, A.A.A., Bibi, S., Kanwal, A., Rania, C., Bilal, Y. & Rehman, J. (2025). Unveiling the potential platinum-based hydrides for solid-state hydrogen storage application: A DFT study, Materi. Sci. Semiconductor Processing, 188, 15, 109214.
Monkhorst, H.J. & Pack, J.D. (1976). Special points for Brillouin-zone integrations. Phys. Rev. B, 13 (12), 5188.
Mouchou, S., Toual, Y., Azouaoui, A., Maouhoubi, A., Masrour, R., Rezzouk, A. (2023). Temperature dependence of thermodynamic and mechanical properties of Fe2RhSi and Fe2RhGe: An ab-initio investigation. Solid State Communications 376: 115374.
Mujica, A., Rubio, A., Munoz, A. & Needs, R.J. (2003). High-pressure phases of group-IV, III–V, and II–VI compounds. Reviews of Modern Physics, 75, 863–912.
Musari, A. (2021). Electronic, mechanical, vibrational and thermodynamic properties of FeXSb (X= Hf and Nb) Half-Heusler alloys from first-principles approach. Solid State Sciences, 122: p. 106755.
Obeidat, A., Alrousan, A. & Abu-Rajou, S. (2025). First-principles study of structural, hydrogen storage, mechanical, electronic, and optical properties of K2NaXH6 (X = Al, As, Bi, Ga, In) double perovskite hydrides, J. Power Sci., 642: 236944.
Orimo, S., Nakamori, Y., Eliseo, J.R., Züttel, A. & Jensen, C.M. (2007). Complex Hydrides for Hydrogen Storage. Chem. Rev., 107, 4111 – 4132.
Orimo, S., Nakamori, Y., Kato, T., Brown, C. & Jensen, C.M. (2006). Intrinsic and mechanically modified thermal stabilities of α-, β- and γ-aluminum trihydrides AlH3. Appl. Phys. A 83, 5–8.
Pan, Y. & Yu, E. (2022). New insight into the structural and physical properties of AlH3, Intl. J. Energy Research. https://doi.org/10.1002/er.8534.
Pan, Y. (2024). Exploring the structural, physical properties and hydrogen storage properties of LiBHx (x = 1 and 4) lithium borohydrides. Ceram. Int., 50(2), 3837–3842.
Penn, D. R. (1962). Wave-number-dependent dielectric function of semiconductors. Phys. Rev. B, 128(5), 2093.
Perdew, J.P., Burke, K. & Ernzerhof, M. (1996), Generalized gradient approximation made Simple, Phys. Rev. Lett. 77, 3865.
Rehman, Z.U., Rehman, M.A., Alomar, S.Y., Rehman, B., Awais, M., Amjad, M., Sikiru, S., Ali, E.M. & Hamad, A. (2024). Hydrogen Storage Capacity of Lead-Free Perovskite NaMTH3 (M T =Sc, Ti, V): A DFT Study, Intl. J. Energy Research, 4009198: 1–14.
Rehman, Z.U., Rehman, M.A., Rehman, B., Sikiru, S., Qureshi, S., Ali, E.M., Awais, M., Amjad, M., Iqbal, I., Rafique, A. & Bibi, S. (2023). Ab initio insight into the physical properties of MgXH3 (X = Co, Cu, Ni) lead‑free perovskite for hydrogen storage application. Environmental Science and Pollution Research, 30: 113889–113902.
Ren, L., Zheng, W., Yang, Y., Xu, X., Jiao, P., Cui, J. (2023). DFT Study on Co–H Bond Dissociation Enthalpies of Cobalt Hydrides in Metal-Catalyzed Hydrogen Atom Transfer Reactions, Russian Journal of Physical Chemistry, 97 (12): 2755 – 2767.
Savić, M., Radaković, J. & Batalović, K. (2017). Study on electronic properties of α-, β- and γ-AlH3 – The theoretical approach. Computational Mater. Sci., 134, 100–108.
Shahzad, M.K., Hussain, S., Khan, M.N., Aslam, M.J., Mohammed, R.M., Tirth, V., Alqahtani, H., Algahtani, A., Al-Mughanam, T. & Azeem, W. (2024). Computational insights of double perovskite Na2CaCdH6 hydride alloy for hydrogen storage applications: a DFT investigation, Scientific Reports, 14:25102.
Sinke, G. C., Walker, L. C., Oetting, F. L. & Stull, D. R. (1967). Thermodynamic properties of aluminum hydride, J. Chem. Phys. 47 (8): 2759–2761.
Song, Y. (2013). New perspectives on potential hydrogen storage materials using high pressure. Phys. Chem. Chem. Phys., 15, 14524 – 14547.
Takeda, Y., Saitoh, Y., Saitoh, H., Machida, A., Aoki, K., Yamagami, H., Muro, T., Kato, Y. & Kinoshita, T. (2011). Electronic structure of aluminum trihydride studied using soft X-ray emission and absorption spectroscopy. Phys. Rev. B, 84, 153102: 1 – 4.
Tatsumi, K., Muto, S., Ikeda, K. & Orimo, S. (2012). Chemical Bonding of AlH3 Hydride by Al-L2,3 Electron Energy-Loss Spectra and First-Principles Calculations, Materials, 5, 566-574
Thapa, R., Ghosh, S., Sinthika, S., Kumar, E.M., Park, N. (2015). Magnetic, elastic and optical properties of zinc peroxide (ZnO2): First principles study. Journal of Alloys and Compounds, 620, 156–163.
Tkacz, M., Filipek, S. & Baranowski, B. (1983). High-pressure synthesis of aluminum-hydride from the elements, Pol. J. Chem., 57, 651 – 653.
Tkacz, M., Palasyuk, T., Graetz, J. & Saxena, S. (2008). High-pressure Raman spectroscopy study of α and γ polymorphs of AlH3. J. Raman Spectroscopy, 39, 922 – 927.
Tufail, D., Ahmed, U., Haleem, M., Amin, B. & Shafiq, M. (2025). DFT study of alkaline earth metals NaXH3 (X = Be, Mg, Ca, Sr) for hydrogen storage capacity, RSC Adv., 15, 337–347.
Turley, J.W. & Rinn, H.W. (1969). The crystal structure of aluminum hydride. Inor. Chem. 8 (1): 18–22.
Usman, M., Wu, A., Bibi, N., Rehman, S., Rehman, M.A., Ahmad, S., Rehman, H.U., Ashraf, M.U., Rehman, Z.U. & Altaf, M. (2024). Hydrogen storage application of Zn‑based hydride ‑ perovskites: a computational insight, Optical and Quantum Electronics, 56, 1478: 1–17.
Vajeeston P., Ravindran P. & Fjellvåg H. (2008). Novel high pressure phases of β-AlH3: A density-functional study, Chem. Mater., 20 (19), 5997 – 6002.
Vajeeston P., Ravindran P. & Fjellvåg H. (2011). Stability enhancement by particle size reduction in AlH3. J. Alloy. Compd. https://org.doi.10.1016/j.jallcom.2010.11.110
Van Setten, M.J., Popa, V.A., de Wijs, G.A. & Brocks, G. (2007). Electronic structure and optical properties of lightweight metal hydrides, Phys. Rev. B, 75, 035204.
Wang, Y., Yan, J.-A. & Chou, M.Y. (2008). Electronic and vibrational properties of γ-AlH3. Phys. Rev. B, 77(1), 014101: 1–8.
Yu, C.-F., Liu, Y.-L., (2025). DFT Study of Au3In and Au3In2 Intermetallic Compounds: Structural Stability, Fracture Toughness, Anisotropic Elasticity, and Thermophysical Properties for Advanced Applications. Materials, 18, 1561. https://doi.org-/10.3390/ma18071561
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Researchers Journal of Science and Technology
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
