Crystal structure study of Perovskite-type LaCoO&lt;inf&gt;3&lt;/inf&gt; electro-catalyst synthesized by Pechini method

Nyamdavaa, E.; Altantsog, P.; Uyanga, E.; Bumaa, B.; Chen, Tsan‐Yao; Lee, Chih‐Hao; Sevjidsuren, G.; Sangaa, D.

doi:10.1109/ifost.2011.6020966

Cited by 5 publications

(4 citation statements)

References 8 publications

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“…The linear thermal expansion coefficients (TEC) of the two unit cell lattice parameters, found by a linear fit to the data in given temperature intervals, are summarized in Table . They are in good agreement with previous XRD studies. , The isotropic thermal expansion calculated from the unit cell volume is in reasonable agreement with those reported by dilatometry, also given in Table for comparison. Significant anisotropy in the thermal expansion of a h and c h is observed for both compositions.…”

Section: Resultssupporting

confidence: 91%

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Chen

Grande

2013

Chem. Mater.

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The crystal structure and the thermal and chemical expansion of rhombohedral La 1−x Sr x CoO 3−δ (x = 0.3, 0.4) perovskite were investigated by in situ high-temperature X-ray diffraction in pure oxygen and nitrogen atmospheres. The crystal structure was confirmed to change from rhombohedral (R3̅ c) to cubic symmetry (Pm3̅ m) with increasing temperature due to a second-order ferroelastic to paraelastic phase transition. The rhombohedral distortion at low temperature causes crystallographic anisotropy, and anisotropic thermal expansion, caused by rectification of the antiferrodistortive tilting and a minor decompression of the CoO 6/2 octahedra is reported. The onset of chemical expansion due to reduction of the oxidation state of Co was observed below the phase transition temperature, which enabled investigation of the crystallographic anisotropy of the chemical expansion. The chemical expansion was significantly larger along the c-axis relative to the a-axis, demonstrating the strong damping of the octahedral tilting with increasing oxygen vacancies induced by the thermal reduction of Co. This phenomenon caused a strong depletion of the ferroelastic phase transition temperature with decreasing partial pressure of oxygen.

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Section: Resultssupporting

confidence: 91%

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Chen

Grande

2013

Chem. Mater.

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“…At present, a lot of efforts were carried out for the synthesis of perovskite with improved physical and chemical properties. LaBO 3 (B = Mn and Co) oxides have been evaluated with materials synthesized through methods such as pechini [8], sol-gel [9], citrate gel [10], and wet impregnation [5] methods.…”

Section: Introductionmentioning

confidence: 99%

Lanthanum-Based Perovskite-Type Oxides La_1−xCe_xBO₃(B = Mn and Co) as Catalysts: Synthesis and Characterization

Erdenee

Uyanga

Sevjidsuren

et al. 2017

Journal of Nanomaterials

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La1−xCexCoO3(x= 0, 0.2, 0.4) and La1−xCexMnO3(x= 0, 0.2) perovskite-type oxides were prepared by sol-gel process. Characterization techniques EDS, FTIR, XRD, BET, and XPS experiments were performed to survey the composition, bulk structure, and the surface properties of perovskites. The reduction behavior, thermal stability, and catalytic activity were studied by H2-TPR and catalytic performance. All synthesized samples showed well crystalline perovskite structure, 8–22 nm crystallite sizes, and SSA with 2–27 m2 g−1. The XRD results showed that the Ce substitution promoted the structural transformation for LaCoO3from rhombohedral into cubic and for LaMnO3no change in lattice geometry. Substitution with cerium (x= 0.2) showed smaller crystallite size, higher SSA, and the highest reducibility and catalytic activity for LaCoO3.

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“…All supercell models of the LSCO/LSMO bilayers are constructed in two steps. (1) We begin with the bulk structure (240 atoms) of perovskite LaCoO 3 with R 3̅ c space-group symmetry obtained from the Materials Project as the template model, replacing the Co atoms located in the lower half of the LaCoO 3 structure with Mn atoms to create a LaCoO 3 /LaMnO 3 bilayer. The choice of 240 atoms strikes a balance between model accuracy and computational efficiency, given the resource-intensive nature of DFT calculations.…”

Section: Methodsmentioning

confidence: 99%

“…The atomic SOAP descriptor 41 is used to encode the local microscopic atomic geometries using the local expansion of a Gaussian-smeared atomic density with orthonormal functions based on spherical harmonics and a radial basis function. We obtained SOAP descriptors with a dimensionality of 7380 for each structure.…”

Section: ■ Methodsmentioning

confidence: 99%

Unraveling the Correlation between the Interface Structures and Tunable Magnetic Properties of La_1–xSr_xCoO_3−δ/La_1–xSr_xMnO_3−δ Bilayers Using Deep Learning Models

Sun,

Lordi,

Takamura

et al. 2024

ACS Appl. Mater. Interfaces

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Perovskite oxides are gaining significant attention for use in next-generation magnetic and ferroelectric devices due to their exceptional charge transport properties and the opportunity to tune the charge, spin, lattice, and orbital degrees of freedom. Interfaces between perovskite oxides, exemplified by La 1−x Sr x CoO 3−δ /La 1−x Sr x MnO 3−δ (LSCO/LSMO) bilayers, exhibit unconventional magnetic exchange switching behavior, offering a pathway for innovative designs in perovskite oxide-based devices. However, the precise atomic-level stoichiometric compositions and chemophysical properties of these interfaces remain elusive, hindering the establishment of surrogate design principles. We leverage first-principles simulations, evolutionary algorithms, and neural network searches with on-the-fly uncertainty quantification to design deep learning model ensembles to investigate over 50,000 LSCO/LSMO bilayer structures as a function of oxygen deficiency (δ) and strontium concentration (x). Structural analysis of the low-energy interface structures reveals that preferential segregation of oxygen vacancies toward the interfacial La 0.7 Sr 0.3 CoO 3−δ layers causes distortion of the CoO x polyhedra and the emergence of magnetically active Co 2+ ions. At the same time, an increase in the Sr concentration and a decrease in oxygen vacancies in the La 0.7 Sr 0.3 MnO 3−δ layers tend to retain MnO 6 octahedra and promote the formation of Mn 4+ ions. Electronic structure analysis reveals that the nonuniform distributions of Sr ions and oxygen vacancies on both sides of the interface can alter the local magnetization at the interface, showing a transition from ferromagnetic (FM) to local antiferromagnetic (AFM) or ferrimagnetic regions. Therefore, the exotic properties of La 1−x Sr x CoO 3−δ /La 1−x Sr x MnO 3−δ are strongly coupled to the presence of hard/soft magnetic layers, as well as the FM to AFM transition at the interface, and can be tuned by changing the Sr concentration and oxygen partial pressure during growth. These insights provide valuable guidance for the precise design of perovskite oxide multilayers, enabling tailoring of their functional properties to meet specific requirements for various device applications.

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Crystal structure study of Perovskite-type LaCoO<inf>3</inf> electro-catalyst synthesized by Pechini method

Cited by 5 publications

References 8 publications

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Lanthanum-Based Perovskite-Type Oxides La_1−xCe_xBO₃(B = Mn and Co) as Catalysts: Synthesis and Characterization

Unraveling the Correlation between the Interface Structures and Tunable Magnetic Properties of La_1–xSr_xCoO_3−δ/La_1–xSr_xMnO_3−δ Bilayers Using Deep Learning Models

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Crystal structure study of Perovskite-type LaCoO<inf>3</inf> electro-catalyst synthesized by Pechini method

Cited by 5 publications

References 8 publications

Anisotropic Chemical Expansion of La1–xSrxCoO3−δ

Anisotropic Chemical Expansion of La1–xSrxCoO3−δ

Lanthanum-Based Perovskite-Type Oxides La1−xCexBO3(B = Mn and Co) as Catalysts: Synthesis and Characterization

Unraveling the Correlation between the Interface Structures and Tunable Magnetic Properties of La1–xSrxCoO3−δ/La1–xSrxMnO3−δ Bilayers Using Deep Learning Models

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Product

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About

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Anisotropic Chemical Expansion of La_1–xSr_xCoO_3−δ

Lanthanum-Based Perovskite-Type Oxides La_1−xCe_xBO₃(B = Mn and Co) as Catalysts: Synthesis and Characterization

Unraveling the Correlation between the Interface Structures and Tunable Magnetic Properties of La_1–xSr_xCoO_3−δ/La_1–xSr_xMnO_3−δ Bilayers Using Deep Learning Models