Characterization of magnesium doped lanthanum orthoniobate synthesized by molten salt route

Mielewczyk‐Gryń, Aleksandra; Wachowski, Sebastian; Zagórski, Krzysztof; Jasiński, Piotr; Gazda, Maria

doi:10.1016/j.ceramint.2015.02.121

Cited by 20 publications

(33 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are also indications of an increase in the apparent activation energy in the of LCNSO10 data for the monoclinic phase compared to LaNbO4 and A-site acceptor doped LaNbO4 38,39,43 . According to Mielewczyk-Gryn et al 32 increasing the Sb concentration results in higher spontaneous strain in the monoclinic polymorph.…”

Section: Discussionmentioning

confidence: 88%

“…Table 2 and literature data for undoped, Ca-doped 38,59 or Sr-doped Ta substituted lanthanum niobate 26 ). Interestingly, the case of Mg-doping 39 is an exception showing an activation energy of 0.74 eV. By taking the effects of the structural change into account, Fjeld et al [19] showed that the enthalpy of mobility of the protons increases from approximately 0.4eV in the tetragonal phase to approximately 0.6 eV in the monoclinic phase.…”

Section: Discussionmentioning

confidence: 99%

“…it has been shown that Mg doping can substantially improve conductivity levels in lanthanum orthoniobate 39 . Finally, since grain boundaries hinder total conductivity an improvement of the material performance is possible through optimization of the existing synthesis method or by choosing a different synthesis route.…”

Section: Discussionmentioning

confidence: 99%

“…Out of this group lanthanum orthoniobate is considered to be among the best materials combining appreciable proton conductivity and chemical stability 22,[24][25][26][27] , reaching conductivity close to 10 -3 S/cm at 900 °C under wet conditions 22 . Doping and substitutions in lanthanum niobate, both alio-and isovalent, have a substantial influence on these materials properties and much effort to understand the influence of dopants on structural [24][25][26][28][29][30][31][32][33][34] and electrical [22][23][24][25][26][27][35][36][37][38][39][40][41][42][43] properties have been made. Lanthanum orthoniobate undergoes a structural phase transition at about 500 °C, which is accompanied by a decrease in the activation energy of the conductivity 37,39,43 and nearly a twofold change of the thermal expansion coefficient (TEC) [24][25][26]29 .…”

mentioning

confidence: 99%

See 3 more Smart Citations

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

et al. 2016

View full text Add to dashboard Cite

The results of ionic transport measurements for the lanthanum orthoniobate substituted with 10 and 30 mol% of antimony (LaNb0.9Sb0.1O4 and LaNb0.7Sb0.3O4) are presented and discussed. The influence of calcium co-doping on these properties has also been analysed. It has been shown that for the investigated material protonic conductivity predominates at temperatures up to 800 °C in oxidizing atmospheres, in wet conditions. Maximum observed protonic conductivity reaches ~10-4 S/cm at 800 °C (in humidified air); in the dry conditions the increasing influence of oxygen vacancies and holes is detected. Oxygen self-diffusivity has also been analysed by isotopic exchange to investigate the possible diffusion paths.

show abstract

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Thermal incompatibility, which yields from a change of the expansion coefficient can lead to strain, cracking or even a total failure of the electrochemical cell . Another parameter that changes with the transition is the activation energy of protonic conductivity, which lowers when the system has a higher order of symmetry . This affects the protonic conductivity of the material.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Structural Properties of LaNb_1‐xAs_xO₄ Ceramics

et al. 2019

View full text Add to dashboard Cite

Lanthanum niobate substituted with arsenic was synthesized by three methods: solid state reaction from binary oxides and two different methods combining co‐precipitation and solid‐state reaction. In the first of the combined methods LaNb1‐xAsxO4 was synthesized from LaAsO4, obtained from co‐precipitation method, and lanthanum and niobium oxides. In the second LaNbO4 was first synthesized from binary oxides and then mixed with LaAsO4 and fired in the second step to obtain the final material. Single phase materials could not be synthesized via solid‐state synthesis, whilst it was possible with both of the combined methods. Structural parameters of the materials obtained with both methods were similar what shows that they do not relate to the synthesis method. Ceramics obtained with both combined methods were dense, however, the density of the ceramics formed from LaAsO4 and LaNbO4 was higher.

show abstract

High‐Temperature Proton Conduction in LaSbO₄

Winiarz

Dzierzgowski

Mielewczyk‐Gryń

et al. 2021

Chemistry A European J

View full text Add to dashboard Cite

Lanthanum orthoantimonate was synthesized using as olid-state synthesis method.T oe nhancet he possible protonic conductivity,s amples with the addition of 1mol %C ai nL a-site were also prepared. The structure was studied by the meanso fX-ray diffraction, which showedt hat both specimens weres ingle phase. The materials crystallized in the space group P2 1 /n. Dilatometry revealedt hat the materiale xpanded non-linearly with the temperature. The nature of this deviation is unknown; however,t he calculated linearf raction thermal expansion coefficient was 9.56 10 À6 K À1 .E lectrical properties studies showedt hat the material is ap rotonc onductor in oxidizing conditions, which was confirmed both by temperature studiesi nw et in dry air,b ut also by the H/D isotopee xchangee xperiment. The conductivity was rather modest, peakinga tt he order of 10 À6 Scm À1 at 800 8C, but this could be further improved by microstructure and doping optimization.T his is the first time protonic conductivity in lanthanum orthoantimonates is reported. Proton conducting ceramics (PCCs) are materials exhibiting ionic conductivityi nw hichp roton (H +)i sacharge carrier. [1] This class of materials has gathered interest over the years for their potential applications.E specially the so-called triple conductingo xides, that is, materials with three mobile charge carriers (protons, oxygen ions, and electron/electron holes) were discovered and studied as potential electrode materials. [2-5] The increased interest led to developing highly-efficient fuel cells [5-7] and steam electrolyzers. [8] This interest stems from the fact that PCC-based devices can operate with high efficiencies while being cost-competitive in comparison to traditional solid oxide fuel cells. [5, 9] Apart from that, new typeso fe lectrochemical devices have been developed. Such devicesc an be used for the synthesis of ammonia, [10, 11] conversion of methane into aromaticsi namembraner eactor, [12] or thermo-electrochemical production of hydrogen from methane. [13]

show abstract

Characterization of magnesium doped lanthanum orthoniobate synthesized by molten salt route

Cited by 20 publications

References 39 publications

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

Fabrication and Structural Properties of LaNb_1‐xAs_xO₄ Ceramics

High‐Temperature Proton Conduction in LaSbO₄

Contact Info

Product

Resources

About

Characterization of magnesium doped lanthanum orthoniobate synthesized by molten salt route

Cited by 20 publications

References 39 publications

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

Influence of Sb-substitution on ionic transport in lanthanum orthoniobates

Fabrication and Structural Properties of LaNb1‐xAsxO4 Ceramics

High‐Temperature Proton Conduction in LaSbO4

Contact Info

Product

Resources

About

Fabrication and Structural Properties of LaNb_1‐xAs_xO₄ Ceramics

High‐Temperature Proton Conduction in LaSbO₄