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Journal of Advanced Ceramics 2022, 11(10): 1613-1625 https://doi.org/10.1007/s40145-022-0635-x
Research Article | Open Access | Issue | Published: 24 September 2022

Sol–gel approach to low-temperature synthesis of single-phase metastable La2Ga3O7.5 melilite with enhanced grain-boundary oxide ionic conductivity via a kinetically favorable mechanism

Show Author's Information Yuan ZHANG,  Longfei ZHAO,  Zhupeng YE,  Yanwei ZENG( )
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
Keywords:
melilite, La2Ga3O7.5, low temperature synthesis, gel-precursor, meta-stability, kinetic mechanism
Cite this article:
ZHANG Y, ZHAO L, YE Z, et al. Sol–gel approach to low-temperature synthesis of single-phase metastable La2Ga3O7.5 melilite with enhanced grain-boundary oxide ionic conductivity via a kinetically favorable mechanism. Journal of Advanced Ceramics, 2022, 11(10): 1613-1625. https://doi.org/10.1007/s40145-022-0635-x
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Abstract Full text Electronic supplementary material About this article

Starting with the stoichiometric and highly homogeneous gel-precursor, single-phase metastable melilite La2Ga3O7.5, as the end-member of solid solution La1+xSr1−xGa3O7+x/2 (0 ≤ x ≤ 1), has been synthesized by solid-state reaction at 700 ℃ for 2 h via a kinetically favorable mechanism and characterized by X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), AC impedance spectroscopy, etc. It has been revealed that the as-synthesized melilite La2Ga3O7.5 shows an orthorhombic symmetry with crystal cell parameters a = 11.4690(1) Å, b = 11.2825(4) Å, and c = 10.3735(4) Å, while has more Raman active modes than LaSrGa3O7 with a tetragonal structure, which was also synthesized under the same conditions for comparison, but tends to slowly decompose into perovskite LaGaO3 and Ga2O3 when annealed at 700 ℃ for over 20 h driven by its meta-stability. Moreover, the metastable La2Ga3O7.5 shows a higher XPS binding energy for the excess oxide ions in the crystal structure than those at normal lattice sites. Its intrinsic grain oxide ion conductivity can reach as high as 0.04 and 0.51 mS·cm–1 at 550 and 700 ℃, respectively, characterized by a simple Arrhenius relationship ln(σT)–1/T with invariable activation energy, Ea = 1.22 eV, over the temperature range from 300 to 700 ℃, along with an apparent grain boundary conductivity that is about double that from the grains thanks to the clean grain boundaries. This paper provides a new strategic approach to the synthesis of complex oxides that may be of high performance but are difficultly achieved by the conventional ceramic method at high temperatures.


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About this article

Sol–gel approach to low-temperature synthesis of single-phase metastable La2Ga3O7.5 melilite with enhanced grain-boundary oxide ionic conductivity via a kinetically favorable mechanism

Show Author's information Yuan ZHANG, Longfei ZHAO, Zhupeng YE, Yanwei ZENG( )
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China

Abstract

Starting with the stoichiometric and highly homogeneous gel-precursor, single-phase metastable melilite La2Ga3O7.5, as the end-member of solid solution La1+xSr1−xGa3O7+x/2 (0 ≤ x ≤ 1), has been synthesized by solid-state reaction at 700 ℃ for 2 h via a kinetically favorable mechanism and characterized by X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), AC impedance spectroscopy, etc. It has been revealed that the as-synthesized melilite La2Ga3O7.5 shows an orthorhombic symmetry with crystal cell parameters a = 11.4690(1) Å, b = 11.2825(4) Å, and c = 10.3735(4) Å, while has more Raman active modes than LaSrGa3O7 with a tetragonal structure, which was also synthesized under the same conditions for comparison, but tends to slowly decompose into perovskite LaGaO3 and Ga2O3 when annealed at 700 ℃ for over 20 h driven by its meta-stability. Moreover, the metastable La2Ga3O7.5 shows a higher XPS binding energy for the excess oxide ions in the crystal structure than those at normal lattice sites. Its intrinsic grain oxide ion conductivity can reach as high as 0.04 and 0.51 mS·cm–1 at 550 and 700 ℃, respectively, characterized by a simple Arrhenius relationship ln(σT)–1/T with invariable activation energy, Ea = 1.22 eV, over the temperature range from 300 to 700 ℃, along with an apparent grain boundary conductivity that is about double that from the grains thanks to the clean grain boundaries. This paper provides a new strategic approach to the synthesis of complex oxides that may be of high performance but are difficultly achieved by the conventional ceramic method at high temperatures.

Keywords: melilite, La2Ga3O7.5, low temperature synthesis, gel-precursor, meta-stability, kinetic mechanism

References(41)

[1]
Steele BCH, Heinzel A. Materials for fuel-cell technologies. Nature 2001, 414: 345-352.
DOI Google Scholar
[2]
Wachsman ED, Lee KT. Lowering the temperature of solid oxide fuel cells. Science 2011, 334: 935-939.
DOI Google Scholar
[3]
Bouwmeester HJM. Dense ceramic membranes for methane conversion. Catal Today 2003, 82: 141-150.
DOI Google Scholar
[4]
Jiang H, Wang H, Werth S, et al. Simultaneous production of hydrogen and synthesis gas by combining water splitting with partial oxidation of methane in a hollow-fiber membrane reactor. Angew Chem Int Ed Engl 2008, 47: 9341-9344.
DOI Google Scholar
[5]
Liu WH, Geng SP, Zhang WD, et al. Experimental and theoretical solid-state 29Si NMR studies on defect structures in La9.33+x(SiO4)6O2+1.5x apatite oxide ion conductors. Inorg Chem 2021, 60: 16817-16825.
DOI Google Scholar
[6]
Chen S, Huang ZL, Wu CS, et al. Preparation of praseodymium-doped La9.33(SiO4)6O2 apatite-type solid electrolytes and analysis of the conductivity mechanism. IOP Conf Ser: Earth Environ Sci 2021, 844: 012006.
DOI Google Scholar
[7]
Cheng JH, Bao WT, Han CL, et al. A novel electrolyte for intermediate solid oxide fuel cells. J Power Sources 2010, 195: 1849-1853.
DOI Google Scholar
[8]
Canu G, Giannici F, Chiara A, et al. Characterisation of scheelite LaW0.16Nb0.84O4.08 ion conductor by combined synchrotron techniques: Structure, W oxidation state and interdiffusion. J Alloys Compd 2021, 857: 157532.
DOI Google Scholar
[9]
Li J, Pan FJ, Geng SP, et al. Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO4+δ. Nat Commun 2020, 11: 4751.
DOI Google Scholar
[10]
Zhou L, Xu J, Allix M, et al. Development of melilite-type oxide ion conductors. Chem Rec 2020, 20: 1117-1128.
DOI Google Scholar
[11]
Rozumek M, Majewski P, Schluckwerder H, et al. Electrical conduction behavior of La1+xSr1–xGa3O7–δ melilite-type ceramics. J Am Ceram Soc 2004, 87: 1795-1798.
DOI Google Scholar
[12]
Rozumek M, Majewski P, Sauter L, et al. La1+xSr1–xGa3O7–δ melilite-type ceramics—Preparation, composition, and structure. J Am Ceram Soc 2004, 87: 662–669.
DOI Google Scholar
[13]
Kuang XJ, Green MA, Niu HJ, et al. Interstitial oxide ion conductivity in the layered tetrahedral network melilite structure. Nat Mater 2008, 7: 498-504.
DOI Google Scholar
[14]
Mancini A, Tealdi C, Malavasi L. Interstitial oxygen in the Ga-based melilite ion conductor: A neutron total scattering study. Int J Hydrog Energy 2012, 37: 8073-8080.
DOI Google Scholar
[15]
Xu J, Kuang X, Véron E, et al. Localization of oxygen interstitials in CeSrGa3O7+δ melilite. Inorg Chem 2014, 53: 11589-11597.
DOI Google Scholar
[16]
Wei FX, Williams T, An T, et al. Observation of atomic scale compositional and displacive modulations in incommensurate melilite electrolytes. J Solid State Chem 2013, 203: 291-296.
DOI Google Scholar
[17]
Park HJ, Kim TG, Kwak C, et al. Sr2(Mg1−xGax)Ge2O7+0.5x: Melilite-type oxygen ionic conductor associated with fivefold coordinated germanium and gallium. J Power Sources 2015, 275: 884-887.
DOI Google Scholar
[18]
Tealdi C, Mustarelli P, Islam MS. Layered LaSrGa3O7-based oxide-ion conductors: Cooperative transport mechanisms and flexible structures. Adv Funct Mater 2010, 20: 3874-3880.
DOI Google Scholar
[19]
Schuett J, Schultze TK, Grieshammer S. Oxygen ion migration and conductivity in LaSrGa3O7 melilites from first principles. Chem Mater 2020, 32: 4442-4450.
DOI Google Scholar
[20]
Wei FX, Gasparyan H, Keenan PJ, et al. Anisotropic oxide ion conduction in melilite intermediate temperature electrolytes. J Mater Chem A 2015, 3: 3091-3096.
DOI Google Scholar
[21]
Li MR, Kuang XJ, Chong SY, et al. Interstitial oxide ion order and conductivity in La1.64Ca0.36Ga3O7.32 melilite. Angew Chem Int Ed Engl 2010, 49: 2362-2366.
DOI Google Scholar
[22]
Xu JG, Wang JH, Tang X, et al. La1+xBa1–xGa3O7+0.5x oxide ion conductor: Cationic size effect on the interstitial oxide ion conductivity in gallate melilites. Inorg Chem 2017, 56: 6897-6905.
DOI Google Scholar
[23]
Liu BB, Ding D, Liu ZB, et al. Synthesis and electrical conductivity of various melilite-type electrolytes Ln1+xSr1–xGa3O7+x/2. Solid State Ion 2011, 191: 68-72.
DOI Google Scholar
[24]
Tealdi C, Chiodelli G, Pin S, et al. Ionic conductivity in melilite-type silicates. J Mater Chem A 2014, 2: 907-910.
DOI Google Scholar
[25]
Xu JG, Li YC, Zhou LJ, et al. Chemical bonding effect on the incorporation and conduction of interstitial oxide ions in gallate melilites. Adv Theory Simul 2019, 2: 1900069.
DOI Google Scholar
[26]
Boyer M, Yang XY, Fernández Carrión AJ, et al. First transparent oxide ion conducting ceramics synthesized by full crystallization from glass. J Mater Chem A 2018, 6: 5276-5289.
DOI Google Scholar
[27]
Xu JG, Wang JH, Rakhmatullin A, et al. Interstitial oxide ion migration mechanism in aluminate melilite La1+xCa1–xAl3O7+0.5x ceramics synthesized by glass crystallization. ACS Appl Energy Mater 2019, 2: 2878-2888.
DOI Google Scholar
[28]
Fan JT, Sarou-Kanian V, Yang XY, et al. La2Ga3O7.5: A metastable ternary melilite with a super-excess of interstitial oxide ions synthesized by direct crystallization of the melt. Chem Mater 2020, 32: 9016-9025.
DOI Google Scholar
[29]
Zhao L, Geng SP, Feng J, et al. Molecular dynamics simulations of oxide ion migration in La2Ga3O7.5 with completely ordered interstitial oxide ions. J Solid State Chem 2021, 302: 122370.
DOI Google Scholar
[30]
Zhong GQ, Shen J, Jiang QY, et al. Synthesis, characterization and thermal decomposition of SbIII–M–SbIII type trinuclear complexes of ethylenediamine-N,N,N’,N’-tetraacetate (M: Co(II), La(III), Nd(III), Dy(III)). J Therm Anal Calorim 2008, 92: 607–616.
DOI Google Scholar
[31]
Steins M, Schmitz W, Uecker R, et al. Crystal structure of strontium lanthanum trigallium heptoxide, (Sr0.5La0.5)2Ga3O7. Zeitschrift Für Kristallographie New Cryst Struct 1997, 212: 76.
DOI Google Scholar
[32]
Sharma SK, Simons B, Yoder HS. Raman study of anorthite, calcium Tschermak’s pyroxene, and gehlenite in crystalline and glassy states. Am Mineral 1983, 68: 1113-1125.
Google Scholar
[33]
Ogorodova LP, Gritsenko YD, Vigasina MF, et al. Thermodynamic properties of natural melilites. Am Mineral 2018, 103: 1945-1952.
DOI Google Scholar
[34]
Sharma SK, Yoder HS Jr., Matson DW. Raman study of some melilites in crystalline and glassy states. Geochimica Cosmochimica Acta 1988, 52: 1961-1967.
DOI Google Scholar
[35]
Price WC. Photoelectron spectroscopy. In: Advances in Atomic and Molecular Physics. Bates DR, Benjamin B, Eds. New York: Academic Press, 1974: 131–171.
DOI
[36]
Ullah Awan S, Hasanain SK, Bertino MF, et al. Ferromagnetism in Li doped ZnO nanoparticles: The role of interstitial Li. J Appl Phys 2012, 112: 103924.
DOI Google Scholar
[37]
Das J, Pradhan SK, Sahu DR, et al. Micro-Raman and XPS studies of pure ZnO ceramics. Phys B 2010, 405: 2492-2497.
DOI Google Scholar
[38]
Sahai A, Goswami N. Probing the dominance of interstitial oxygen defects in ZnO nanoparticles through structural and optical characterizations. Ceram Int 2014, 40: 14569-14578.
DOI Google Scholar
[39]
Chen HM, Bai YX, Zheng LR, et al. Interstitial oxygen defect induced mechanoluminescence in KCa(PO3)3:Mn2+. J Mater Chem C 2020, 8: 6587-6594.
DOI Google Scholar
[40]
Zhu J, Liu G, Liu Z, et al. Unprecedented perovskite oxyfluoride membranes with high-efficiency oxygen ion transport paths for low-temperature oxygen permeation. Adv Mater 2016, 28: 3511-3515.
DOI Google Scholar
[41]
Zhang LH, Sun W, Xu CM, et al. Attenuating a metal–oxygen bond of a double perovskite oxide via anion doping to enhance its catalytic activity for the oxygen reduction reaction. J Mater Chem A 2020, 8: 14091-14098.
DOI Google Scholar
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Publication history

Received: 04 April 2022
Revised: 12 July 2022
Accepted: 17 July 2022
Published: 24 September 2022
Issue date: October 2022

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© The Author(s) 2022.

Acknowledgements

This work was supported by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions, China. We would like to thank Mengyan Chen and Weiwei Wang from Shiyanjia Lab (www.shiyanjia.com) for the XPS and HRTEM analysis.

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