Structure and ionic conductivity of reactively sputtered apatite-type lanthanum silicate thin films

Vieira, M.M.; Oliveira, J.C.; Shaula, A.L.; Trindade, B.; Cavaleiro, A.

doi:10.1016/j.surfcoat.2014.02.064

Cited by 12 publications

(3 citation statements)

References 47 publications

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“…The preparation of La-Si-O apatite-type thin films was described by VIEIRA et al [52] with Si/(La + Si) atomic ratios ranging from 0.36 to 0.43 being produced via the magnetron sputtering in reactive Ar/O discharge gas. The apatite-type lanthanum silicate phase was formed in all as-deposited films upon the annealing at 900°C for 1 h. The lanthanum silicate films obtained by annealing the as-deposited films with lower Si/(La + Si) atomic ratios have a preferential orientation with the c-axis perpendicular to the substrate, while low-intensity diffraction peaks ascribed to La 2 Si 2 O 7 phase were detected in the films deposited with higher Si content.…”

Section: Apatite-type Lanthanium Silicatesmentioning

confidence: 99%

Rare-earth Element-bearing Apatites and Oxyapatites

Ptáček¹

2016

Apatites and Their Synthetic Analogues - Synthesis, Structure, Properties and Applications

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A number of prepared alkaline-earth-rare-earth silicates and germanates also have the structure of apatite type. The fifth chapter of this book then continues with description of synthetic compounds of apatite structure. Attention will be directed to description of rare-earth element bearing apatites and oxyapatites. The structure, properties and preparation of apatite-type silicates, germanates and borates were described. This chapter gives also description of oxygen-rich apatites, which are promising material for electrolytes in solid oxide fuel cells and sensors and explain the basic concepts between structure and conductivity of these compounds. The additional information about application of apatites is given in the last chapter of this book. Furthermore, N-apatite, REE vanadocalcic apatite and apatite type yttrium phosphates were described.

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Section: Apatite-type Lanthanium Silicatesmentioning

confidence: 99%

Rare-earth Element-bearing Apatites and Oxyapatites

Ptáček¹

2016

Apatites and Their Synthetic Analogues - Synthesis, Structure, Properties and Applications

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“…Este eletrólito possui alta condutividade iônica, ou seja, transporta íons oxigênio com mais facilidade em altas temperaturas, superiores a 800°C, o que a seleção de materiais, por exigir materiais que suportem altas temperaturas e sejam resistentes à corrosão. Tais materiais são caros e de difícil processamento (10,11,12) .…”

Section: Introductionunclassified

“…Por este motivo, a pesquisa e desenvolvimento de novos eletrólitos que possam substituir o YSZ e permitam à SOFC operar em temperaturas mais baixas, na faixa de 500-800°C, as chamadas IT-SOFCs ("Intermediate Temperature Solid Oxide Fuel Cells" -Células a combustível de óxido sólido de temperatura intermediária), têm sido alvo de grande interesse na comunidade científica e industrial (10,11) . Entre as promissoras alternativas à substituição do YSZ encontramse os silicatos de terras raras, em especial, o silicato de lantânio tipo apatita.…”

Section: Introductionunclassified

Estudo de síntese de silicato de lantânio tipo apatita pelo método sol-gel seguido de precipitação de Na<sub>2</sub>SiO<sub>3</sub>

Silva¹

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A Deus pela infinita graça e bondade por me conceder a oportunidade de aprender, conviver e crescer como pessoa. A toda a minha família pelo incentivo, apoio, suporte, dedicação, carinho e amor. A Dra. Chieko Yamagata pela orientação, dedicação, apoio, confiança e experiência durante todo o trabalho. A Agatha Mattos Misso pela amizade, companheirismo, incentivo, intercâmbio de conhecimentos, apoio no laboratório e sala de aula. Aos amigos MSc. Jefferson Matsui, MSc. André Piaggio, Dr. Guilherme L. Cordeiro e Dra. Anelyse Arata pela amizade, companheirismo, apoio e agradável convivência durante todo o período. Ao laboratório de Difração de raios X, Dr. Renê Ramos de Oliveira, MSc. Gleicy Lima pelo excelente trabalho e apoio nas análises realizadas. Aos professores Dr. Valter Ussui e Dra. Dolores R. R. Lazar pela oportunidade de ingresso ao IPEN para realização da iniciação científica. Ao Dr. Walter Kenji Yoshito pelo apoio técnico, incentivo e experiência na etapa experimental e durante todo o trabalho. Ao Laboratório de Insumos pela imensa contribuição.

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Studies on morpho-structure and ionic conductivity of apatite-type lanthanum silicate doped with transitional metal cations

Perhaita,

Muresan,

Borodi

et al. 2024

J Electroceram

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Oxy-apatite lanthanum silicates with general formula La10Si5.9M0.1O27±δ (M = Cr3+, Mn4+, Fe3+, Mo6+, W6+; 0.05 ≤ δ ≤ 0.1, coded LaSiMO) were obtained by gel-combustion and they were characterized through electrochemical impedance spectroscopy. The XRD patterns show that all samples adopt apatite structure and crystallize in the hexagonal space group P-3(147) with crystallite sizes ranging from 86 nm to 103 nm. The dopant cations were accommodated at Si position with the highest occupancy factor at O6 sites (responsible in conduction) for LaSiCrO and LaSiFeO apatites. Fe and Cr doped samples contain pure apatite phase while those doped with Mn, Mo, W contain La2SiO5 as secondary phase which act as insulator in conduction process. Based on EPR and ICP-OES investigations we found that Mn, Mo, W cations present multiple oxidation states in the apatite lattice and a lower incorporation degree in comparison with Fe and Cr cations. Local distortions are present in Fe and Cr doped apatite lattices which explains the higher ionic conductivity of these samples. At 500oC, the ionic conductivities, range between 1.15·10− 4 and 3.56·10− 4 S·cm− 1 for samples sintered at 1400oC, values that are higher than un-doped apatite (6.46·10− 5 S·cm− 1). Due to the highest ionic conductivity among the samples, LaSiCrO was additionally sintered at 1500oC and 1600oC in order to investigate the role of temperature on ionic conduction process. The relative density of LaSiCrO was improved from 89.03 to 93.06% and the ionic conductivity reach 0.28·10− 2 S·cm− 1, at 600oC. The results of this study show that apatites doped with Cr and Fe may be used as electrolytes in SOFCs.

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Structure and ionic conductivity of reactively sputtered apatite-type lanthanum silicate thin films

Cited by 12 publications

References 47 publications

Rare-earth Element-bearing Apatites and Oxyapatites

Rare-earth Element-bearing Apatites and Oxyapatites

Estudo de síntese de silicato de lantânio tipo apatita pelo método sol-gel seguido de precipitação de Na<sub>2</sub>SiO<sub>3</sub>

Studies on morpho-structure and ionic conductivity of apatite-type lanthanum silicate doped with transitional metal cations

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