Charge carrier relaxation phenomena and phase transition in La 2 Mo 2 O 9 ceramics investigated by broadband impedance spectroscopy

Kežionis, A.; Petrulionis, Dalius; Kazakevičius, E.; Kazlauskas, Saulius; Žalga, Artūras; Juškėnas, Remigijus

doi:10.1016/j.electacta.2016.07.124

Cited by 12 publications

(4 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our findings indicate that the O1 sites are activated at higher temperatures than O2 and O3, providing extra charge carriers and vacancies initially allowing for increased intra-MoO x motion of oxide ions, which then translates into increased long-range inter-MoO x diffusion. This activation of O1 at higher temperatures agrees well with the recent experimental observations by Kezionis et al 32 They find two processes leading to the bulk conductivity in La 2 Mo 2 O 9 , one below the phase transition (and persisting above it), equivalent to our low temperature process involving O2 and O3, and one which appears above the phase transition, equivalent to our high temperature process involving O1. Our findings also explain why the low temperature process could still be observed at higher temperatures, as this process still remains as a significant part of the overall conductivity mechanism.…”

Section: Chemistry Of Materialssupporting

confidence: 93%

“…49 The obtained values for the jump distance, l, and lifetime, τ, are 2.98 Å and 1.8 ns, respectively. The lifetime found is in good agreement with the relaxation time reported by Kezionis et al 32 for the process occurring at higher temperatures (to which they refer to as the β-process, equivalent to our process involving O1 atoms, vide infra).…”

Section: Chemistry Of Materialssupporting

confidence: 91%

“…Their study involved only a small simulation box consisting of a single β-unit cell and did not investigate explicitly how the mechanisms changed with temperature. Recently, Kezionis et al 32 reported an analysis based on a distribution of relaxation times using broadband impedance spectroscopy. They observed two relaxation processes in La 2 Mo 2 O 9 : one process which is present in both low and high temperature phases, although reaching a maximum around the phase transition, and a different process which dominates in the β-phase.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

et al. 2017

View full text Add to dashboard Cite

Quasielastic neutron scattering (QENS), underpinned by ab-initio molecular dynamics (AIMD) simulations, has been used to directly observe oxide ion dynamics in solid electrolyte La 2 Mo 2 O 9 on the nanosecond timescale, the longest timescale probed in oxide ion conductors by neutron scattering to date. QENS gives the activation energy of 0.61(5) eV for this process, while AIMD simulations reveal that the exchange processes, which ultimately lead to long-range oxide ion diffusion in La 2 Mo 2 O 9 , rely on the flexibility of the coordination environment around Mo 6+ , with oxide ions jumps occurring between vacant sites both within and between Mo coordination spheres. Simulations also differentiate between the crystallographic sites which participate in the oxide ion exchange processes, offering the first atomic-level understanding of the oxide ion dynamics in La 2 Mo 2 O 9 , which is consistent with the macroscopic experimental observations on this material.

show abstract

Section: Chemistry Of Materialssupporting

confidence: 93%

Section: Chemistry Of Materialssupporting

confidence: 91%

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The precise oxide ion migration mechanisms have been intensively investigated by several research groups − at both local and long-range scales. The first clue about the oxide ion migration mechanism was revealed by the large atomic displacement for all the oxygen atoms, from which Corbel et al proposed an oxide migration mechanism in which only O2 and O3 sites were involved in β-La 2 Mo 2 O 9 .…”

Section: Lamox-type Oxide Ion Conductorsmentioning

confidence: 99%

Oxide Ion-Conducting Materials Containing Tetrahedral Moieties: Structures and Conduction Mechanisms

2023

View full text Add to dashboard Cite

This Review presents an overview from the perspective of tetrahedral chemistry on various oxide ion-conducting materials containing tetrahedral moieties which have received continuous growing attention as candidates for key components of various devices, including solid oxide fuel cells and oxygen sensors, due to the deformation and rotation flexibility of tetrahedral units facilitating oxide ion transport. Emphasis is placed on the structural and mechanistic features of various systems ranging from crystalline to amorphous materials, which include a variety of gallates, silicates, germanates, molybdates, tungstates, vanadates, aluminates, niobate, titanates, indium oxides, and the newly reported borates. They contain tetrahedral units in either isolated or linked manners forming different polyhedral dimensionality (0 to 3) with various defect properties and transport mechanisms. The development of oxide ion conductors containing tetrahedral moieties and the elucidation of the roles of tetrahedral units in oxide ion migration have demonstrated diverse opportunities for discovering superior electrolytes for solid oxide fuel cells and other related devices and provided useful clues for uncovering the key factors directing fast oxide ion conduction.

show abstract

Conductivity and Phase Transition Study of Sr²⁺‐Substituted La₂Mo_1.95V_0.05O_9–δ

Tado

Pandey

2020

Physica Status Solidi (b)

View full text Add to dashboard Cite

Solution combustion technique is used for synthesizing La2−xSrxMo1.95V0.05O9−δ (x = 0–0.14). The properties of these compounds are investigated via X‐ray diffraction (XRD), scanning electron microscopy, differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy. No secondary phases are detected in XRD. Complete suppression of αβ phase transition is evident via RT‐XRD and DSC in all doped compounds. Throughout the temperature regime, conductivity is enhanced compared with parent La2Mo2O9. The conductivity plot reveals an Arrhenius to Vogel–Tammann–Fulcher (VTF) type of temperature‐dependent conduction behavior.

show abstract

Charge carrier relaxation phenomena and phase transition in La 2 Mo 2 O 9 ceramics investigated by broadband impedance spectroscopy

Cited by 12 publications

References 30 publications

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

Oxide Ion-Conducting Materials Containing Tetrahedral Moieties: Structures and Conduction Mechanisms

Conductivity and Phase Transition Study of Sr²⁺‐Substituted La₂Mo_1.95V_0.05O_9–δ

Contact Info

Product

Resources

About

Charge carrier relaxation phenomena and phase transition in La 2 Mo 2 O 9 ceramics investigated by broadband impedance spectroscopy

Cited by 12 publications

References 30 publications

Direct Observation of Oxide Ion Dynamics in La2Mo2O9 on the Nanosecond Timescale

Direct Observation of Oxide Ion Dynamics in La2Mo2O9 on the Nanosecond Timescale

Oxide Ion-Conducting Materials Containing Tetrahedral Moieties: Structures and Conduction Mechanisms

Conductivity and Phase Transition Study of Sr2+‐Substituted La2Mo1.95V0.05O9–δ

Contact Info

Product

Resources

About

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

Direct Observation of Oxide Ion Dynamics in La₂Mo₂O₉ on the Nanosecond Timescale

Conductivity and Phase Transition Study of Sr²⁺‐Substituted La₂Mo_1.95V_0.05O_9–δ