Novel two-step processing route combining mechanical alloying and microwave hybrid sintering to fabricate dense La9.33Si2Ge4O26 for SOFCs

Santos, Márcio; Alves, C.F. Almeida; Oliveira, Fernando A. Costa; Marcelo, Teresa; Mascarenhas, João; Cavaleiro, A.; Trindade, B.

doi:10.1016/j.jpowsour.2012.12.101

Cited by 22 publications

(5 citation statements)

References 30 publications

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“…The investigations of apatite-type lanthanum silicates/germanates (ATLS/ATLG) as novel electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) have gained considerable interest owing to their clean energy conversion, high energy efficiency and potential use for developing fuel cell devices. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In contrast to a vacancy mechanism commonly observed for uoriteand perovskite-type oxide ion conductors, such as doped ZrO 2 (e.g. YSZ) 15,16 and doped LaGaO 3 (e.g.…”

Section: Introductionmentioning

confidence: 99%

New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

Yin

Sun

et al. 2014

RSC Adv.

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Section: Introductionmentioning

confidence: 99%

New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

Yin

Sun

et al. 2014

RSC Adv.

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“…Apatite-type lanthanum silicates (ATLS) and apatitetype lanthanum germanates (ATLG), as novel electrolytes for the intermediate temperature solid oxide fuel cells (IT-SOFCs), [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] have been attracting widespread attention of the scientific community due to their clean energy conversions, superior ionic conductivities, excellent long-term stabilities and low processing cost. In contrast to the fact that traditional fluorite and perovskite-type oxide ion conductors have a vacancy conduction mechanism, [16][17][18] apatite-type materials have an especial interstitial oxide ion conduction mechanism, [19,20] which could be responsible for their high oxide-ion conductivities.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature synthesis of apatite-type La _9.33 Ge ₆ O ₂₆ as electrolytes with high conductivity

et al. 2018

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In the present study, high-quality apatite-type La 9.33 Ge 6 O 26 powders are successfully synthesized by a facile moltensalt synthesis method (MSSM) at low temperatures, using LiCl, LiCl/NaCl mixture (mass ratio 1:1) as molten salt, respectively. Experimental results indicate that the optimal mass ratio between reactant and molten salt is 1:2, and LiCl/NaCl mixed molten-salt is more beneficial for forming high-quality La 9.33 Ge 6 O 26 powders than LiCl individual molten-salt. Comparing with the conventional solid-state reaction method (SSRM), the synthesis temperature of apatitetype La 9.33 Ge 6 O 26 powders using the MSSM decreases more than 350 • C, which can effectively avoid Ge loss in the preparation process of precursor powders. Furthermore, the powders obtained by the MSSM are homogeneous, nonagglomerated and well crystallized, which are very favorable for gaining dense pellets in the premise of avoiding Ge loss. On the basis of high-quality precursor powders, the dense and pure ceramic pellets of La 9.33 Ge 6 O 26 are gained at a low temperature of 1100 • C for 2 h, which exhibit higher conductivities (σ 850 • C(LiCl) = 2.3 × 10 −2 S•cm −1 , σ 850 • C(LiCl/NaCl) = 4.9 × 10 −2 S•cm −1 ) and lower activation energies (E a(LiCl) = 1.02 eV, E a(LiCl/NaCl) = 0.99 eV) than that synthesized by the SSRM.

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“…Apatite-type lanthanum silicates (ATLSs) with the general formula La 9.33+x (SiO 4 ) 6 O 2+1.5x (0 ≤ x ≤ 0.67) have been gaining widespread attention owing to their potential applications in gas-sensing and fuel cell devices. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] ATLSs have an especially hexagonal apatite structure (Fig. 1), which is beneficial for conducting oxygen ions.…”

Section: Introductionmentioning

confidence: 99%

Pressure-induced structural evolution of apatite-type La _9.33 Si ₆ O ₂₆

Yin¹,

Yin²,

Sun³

et al. 2018

Chinese Phys. B

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The pressure-induced structural evolution of apatite-type La 9.33 Si 6 O 26 was systematically studied using in situ synchrotron x-ray diffraction (XRD). The XRD spectra indicated that a subtly reversible phase transition from P6 3 /m to P6 3 symmetry occurred at ∼ 13.6 GPa because of the tilting of the SiO 4 tetrahedra under compression. Furthermore, the La 9.33 Si 6 O 26 exhibited a higher axial compression ratio for the a-axis than the c-axis, owing to the different axial arrangement of the SiO 4 tetrahedra. Interestingly, the high-pressure phase showed compressibility unusually higher than that of the initial phase, suggesting that the low P6 3 symmetry provided more degrees of freedom. Moreover, the La 9.33 Si 6 O 26 exhibited a lower phase transition pressure (P T ) and a higher lattice compression than La 10 Si 6 O 27 . Comparisons between La 9.33 Si 6 O 26 and La 10 Si 6 O 27 provided a deeper understanding of the effect of interstitial oxygen atoms on the structural evolution of apatite-type lanthanum silicates (ATLSs).

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Novel two-step processing route combining mechanical alloying and microwave hybrid sintering to fabricate dense La9.33Si2Ge4O26 for SOFCs

Cited by 22 publications

References 30 publications

New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

Low-temperature synthesis of apatite-type La _9.33 Ge ₆ O ₂₆ as electrolytes with high conductivity

Pressure-induced structural evolution of apatite-type La _9.33 Si ₆ O ₂₆

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Novel two-step processing route combining mechanical alloying and microwave hybrid sintering to fabricate dense La9.33Si2Ge4O26 for SOFCs

Cited by 22 publications

References 30 publications

New approach to improve the conductivity of apatite-type lanthanum germanate La9.33Ge6O26 as electrolyte for IT-SOFCs

New approach to improve the conductivity of apatite-type lanthanum germanate La9.33Ge6O26 as electrolyte for IT-SOFCs

Low-temperature synthesis of apatite-type La 9.33 Ge 6 O 26 as electrolytes with high conductivity

Pressure-induced structural evolution of apatite-type La 9.33 Si 6 O 26

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New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

New approach to improve the conductivity of apatite-type lanthanum germanate La_9.33Ge₆O₂₆ as electrolyte for IT-SOFCs

Low-temperature synthesis of apatite-type La _9.33 Ge ₆ O ₂₆ as electrolytes with high conductivity

Pressure-induced structural evolution of apatite-type La _9.33 Si ₆ O ₂₆