Engineering Transport in Manganites by Tuning Local Nonstoichiometry in Grain Boundaries

Chiabrera, Francesco; Garbayo, Íñigo; López‐Conesa, Lluís; Martín, Gemma; Ruiz‐Caridad, Alicia; Walls, Michael; Ruiz‐González, Luisa; Kordatos, Apostolos; Nuñez, Marc; Morata, Álex; Estradé, S.; Chroneos, Alexander; Peiró, Francesca; Tarancón, Albert

doi:10.1002/adma.201805360

Cited by 33 publications

(51 citation statements)

References 59 publications

(92 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It must be noted here that the presence of high angle grain boundaries in the LSF20 thin film may locally modify the point defect concentration, as was previously found in other MIEC materials (see Section S3, Supporting Information, for the discussion about the effects of homogeneity of the thin films and its effects on the ellipsometric parameters). [ 9,35 ] Overall, it is possible to conclude that the deposited LSF layers provide a representative set of samples for the study of the defect chemistry in LSF thin films.…”

Section: Resultsmentioning

confidence: 99%

“…[ 8 ] Besides, the presence of heterogeneous and homogenous interfaces in thin films was shown to drastically impact defect concentrations in such layers, which gives rise to deviations from bulk defect chemistry and, eventually, to new and unexpected properties. [ 9–11 ] Therefore, the knowledge and quantification of the chemical reactions that dominate the defect concentration in oxide thin films (i.e., defect chemistry) is essential for understanding the material behavior and for engineering their properties. This is especially relevant at intermediate‐to‐low temperatures (below 500 °C), where a high electrochemical activity and the nanometric dimensions of the thin films allow the point defect equilibrium with the environment, [ 12 ] hampering the use of the high temperature defect chemistry model from the bulk counterpart.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pushing the Study of Point Defects in Thin Film Ferrites to Low Temperatures Using In Situ Ellipsometry

Tang

Chiabrera

Morata

et al. 2021

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

point defects, imperfections, and higher dimensional extended defects are known to severely impact the overall functional properties. [3,4] As a matter of example, oxygen vacancies were shown to enhance oxygen conductivity in oxide-ion electrolytes [5] or to boost oxygen incorporation and catalytic activity in mixed ionic electronic conductors (MIECs) [6,7] while weakening electronic and magnetic order in ferromagnetic oxides. [8] Besides, the presence of heterogeneous and homogenous interfaces in thin films was shown to drastically impact defect concentrations in such layers, which gives rise to deviations from bulk defect chemistry and, eventually, to new and unexpected properties. [9-11] Therefore, the knowledge and quantification of the chemical reactions that dominate the defect concentration in oxide thin films (i.e., defect chemistry) is essential for understanding the material behavior and for engineering their properties. This is especially relevant at intermediate-to-low temperatures (below 500 °C), where a high electrochemical activity and the nanometric dimensions of the thin films allow the point defect equilibrium with the environment, [12] hampering the use of the high temperature defect chemistry model from the bulk counterpart. A paradigmatic example of the large effect of point defects on the functional properties of transitional metal oxides can be found in the La 1−x Sr x FeO 3−δ (LSF) model family. LSF compounds crystalize in a perovskite ABO 3 structure and find application in many renewable energy technologies, such as solid oxide fuel cells (SOFC), [13] or electrochemical and photoelectrochemical water splitting. [14,15] In LSF, the substitution of trivalent La by divalent Sr gives rise to the generation of electronic holes and/or oxygen vacancies for electronic compensation, depending on the electrochemical equilibrium with the oxygen partial pressure of the environment. Interestingly, both point defects were found to be strongly correlated to many functional properties of LSF. For instance, the increase of holes concentration was found responsible for a large modification of the electronic structure, [16] affecting not just the electronic and magnetic transport properties [17] but also the oxygen evolution properties in aqueous media. [15] Meanwhile, oxygen vacancies were shown to take part into the rate-limiting step of oxygen incorporation at high temperature. [18] For these reasons, the development of a reliable and flexible in situ method for tracking the point defects of LSF thin films on any substrate and environment is fundamental for tailoring their properties. Unveiling point defects concentration in transition metal oxide thin films is essential to understand and eventually control their functional properties, employed in an increasing number of applications and devices. Despite this unquestionable interest, there is a lack of available experimental techniques able to estimate the defect chemistry and equilibrium constants in such oxides at intermediate-to-low temperatures. In ...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pushing the Study of Point Defects in Thin Film Ferrites to Low Temperatures Using In Situ Ellipsometry

Tang

Chiabrera

Morata

et al. 2021

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

show abstract

“…The VAN combines the excellent ionic conductivity of SDC with the great oxygen affinity of the LSM (typically hindered by its poor oxygen diffusivity) resulting in a perfect synergy that provides an ideal electrode material by design. 38 This job-sharing effect is further enhanced by the unique VAN microstructure, which is characterized by no tortuosity for mass transport and by maximized triple-phase boundary density (>10 6 cm•cm -2 , cf. Fig.…”

Section: Resultsmentioning

confidence: 99%

A heavily subtituted manganite in an ordered nanocomposite for long-term energy applications

Baiutti

Chiabrera

Acosta

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of superior energy materials. Vertically aligned nanocomposites are characterized by a coherent, dense array of vertical interfaces, which allows for the extension of local effects to the whole volume of the material. Here, we use such a unique architecture to fabricate highly electrochemically active nanocomposites of lanthanum strontium manganite and doped ceria with unprecedented stability and straight applicability as functional layers in solid state energy devices. Direct evidence of synergistic local effects for enhancing the electrochemical performance, stemming from the highly ordered phase alternation, is given here for the first time using atom-probe tomography combined with oxygen isotopic exchange. Interface-induced cationic substitution, enabling lattice stabilization, is presented as the origin of the observed long-term stability. These findings reveal a novel route for materials nano-engineering based on the coexistence between local disorder and long-range arrangement.

show abstract

“…37 The VAN combines the excellent ionic conductivity of SDC with the great oxygen affinity of the LSM (typically hindered by its poor oxygen diffusivity) resulting in a perfect synergy that provides an ideal electrode material by design. 38 This job-sharing effect is further enhanced by the unique VAN microstructure, which is characterized by no tortuosity for mass transport and by maximized triple-phase boundary density (>10 6 cm•cm -2 , cf. Fig.…”

mentioning

confidence: 99%

“…fast grain boundary oxygen diffusion). 38 In order to quantify this qualitative picture, the measured diffusion profiles (integrated over the area between the dotted lines in (note that no information on the ion diffusivity is accessible by tracer method for SDC since these regions saturate owing to the very fast transport kinetics). Similar results on a different 2D cross-section are reported in Supplementary Figure 4.…”

mentioning

confidence: 99%

A Heavily Substituted Manganite in an Ordered Nanocomposite for Long-Term Energy Applications

Baiutti

Chiabrera²,

Acosta³

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

<div>The implementation of nano-engineered composite oxides opens up the way towards the development of</div><div>a novel class of superior energy materials. Vertically aligned nanocomposites are characterized by a</div><div>coherent, dense array of vertical interfaces, which allows for the extension of local effects to the whole</div><div>volume of the material. Here, we use such a unique architecture to fabricate highly electrochemically</div><div>active nanocomposites of lanthanum strontium manganite and doped ceria with unprecedented stability</div><div>and straight applicability as functional layers in solid state energy devices. Direct evidence of synergistic</div><div>local effects for enhancing the electrochemical performance, stemming from the highly ordered phase</div><div>alternation, is given here for the first time using atom-probe tomography combined with oxygen isotopic</div><div>exchange. Interface-induced cationic substitution, enabling lattice stabilization, is presented as the origin</div><div>of the observed long-term stability. These findings reveal a novel route for materials nano-engineering</div><div>based on the coexistence between local disorder and long-range arrangement.</div>

show abstract

Engineering Transport in Manganites by Tuning Local Nonstoichiometry in Grain Boundaries

Cited by 33 publications

References 59 publications

Pushing the Study of Point Defects in Thin Film Ferrites to Low Temperatures Using In Situ Ellipsometry

Pushing the Study of Point Defects in Thin Film Ferrites to Low Temperatures Using In Situ Ellipsometry

A heavily subtituted manganite in an ordered nanocomposite for long-term energy applications

A Heavily Substituted Manganite in an Ordered Nanocomposite for Long-Term Energy Applications

Contact Info

Product

Resources

About