Effects of Fe substitution by Nb on physical properties of BaFeO3: A DFT+U study

Cherair, Imène; Iles, Nadia; Rabahi, L.; Kellou, A.

doi:10.1016/j.commatsci.2016.10.018

Cited by 12 publications

(16 citation statements)

References 61 publications

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“…For all the used approaches (DFT+U and hybrid functionals), the FM order is always the lowest energy state (all the energies relative to the FM one are positive in Table II) and the next lowest energy phase is the A-AFM. Our findings are in agreement with the previous theoretical works of Li et al 54 , Ribeiro et al 37 and Cherair et al 51 . It can be noticed that the energy differences between the magnetic orders obtained with DFT+U are more pronounced that those obtained with hybrid functionals.…”

Section: A Bulk Propertiessupporting

confidence: 94%

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Strain induced Jahn-Teller distortions in BaFeO3 : A first-principles study

Cherair,

Bousquet,

Schmitt

et al. 2017

Preprint

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The effect of epitaxial strain on structural, magnetic and electronic properties of BaFeO3 perovskite oxide are investigated from first principles calculations, using the Density Functional Theory (DFT) plus the Hubbard approach (DFT+U) within the Generalized Gradient Approximation (GGA). Hybrid functional calculations, based on mixed exact Hartree-Fock (HF) and DFT exchange energy functionals, are also performed. For the ground state calculations,the DFT+U is found more suitable to describe the half metallic and ferromagnetic state of cubic BaFeO3. The possible occurence of oxygen octahedra rotations, Jahn-Teller distortions and charge orderings through biaxial strain are explored. The obtained results reveal that the Jahn-teller distortion is induced under tensile biaxial strain while the oxygen octahedra rotations and breathing are unusualy not observed. Then, the strained BaFeO3 is considered as a particular Jahn-Teller distorted perovskite with exceptional properties when compared to CaFeO3 and SrFeO3. These findings lead to a strain engineering of the JT distortions in BaFeO3, and thus for high fundamental and technological interests.

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Section: A Bulk Propertiessupporting

confidence: 94%

“…Our calculations show a magnetic moment of 4 µ B (U = 4 eV). This result is consistent with the t 2g 3 ↑ e g 1 ↑ electronic configuration of Fe 4+ and with recent works on BaFeO3 18,51 .…”

Section: A Bulk Propertiessupporting

confidence: 93%

Strain induced Jahn-Teller distortions in BaFeO3 : A first-principles study

Cherair,

Bousquet,

Schmitt

et al. 2017

Preprint

Self Cite

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“…To elucidate the formation mechanism of Nb-deficient BCFN NPs on the BCFN air electrode, bulk and surface properties of various Ba-containing perovskites were studied. Stoichiometric BaBO 3 (B = Co, Fe, or Nb) 61 with a cubic structure ( ) was first optimized (Supplementary Table 4 and Supplementary Fig. 12 ).…”

Section: Discussionmentioning

confidence: 99%

“…A > 15 Å vacuum space and (3 × 3 × 1) k-point meshes were employed for surface calculations. Stoichiometric BaBO 3 perovskites (B = Co, Fe, or Nb) with a cubic structure ( ) (4 Ba, 4 B, O 12 atoms) 61 were optimized first to examine the surface energy of 16-layered BO-terminated surfaces (i.e., CoO-, FeO-, and NbO-termination) (Supplementary Table 4 and Supplementary Figs. 12 and 13 ).…”

Section: Methodsmentioning

confidence: 99%

Surface restructuring of a perovskite-type air electrode for reversible protonic ceramic electrochemical cells

et al. 2022

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Reversible protonic ceramic electrochemical cells (R-PCECs) are ideally suited for efficient energy storage and conversion; however, one of the limiting factors to high performance is the poor stability and insufficient electrocatalytic activity for oxygen reduction and evolution of the air electrode exposed to the high concentration of steam. Here we report our findings in enhancing the electrochemical activity and durability of a perovskite-type air electrode, Ba0.9Co0.7Fe0.2Nb0.1O3-δ (BCFN), via a water-promoted surface restructuring process. Under properly-controlled operating conditions, the BCFN electrode is naturally restructured to an Nb-rich BCFN electrode covered with Nb-deficient BCFN nanoparticles. When used as the air electrode for a fuel-electrode-supported R-PCEC, good performances are demonstrated at 650 °C, achieving a peak power density of 1.70 W cm−2 in the fuel cell mode and a current density of 2.8 A cm−2 at 1.3 V in the electrolysis mode while maintaining reasonable Faradaic efficiencies and promising durability.

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“…Perovskite niobates, with the composition of ANbO 3 (A = Li, K, Na, Ag), are widely used in lead-free piezoelectric and nonlinear optical devices due to their excellent ferroelectricity and nonlinear optical properties [9][10][11][12][13][14]. Previous theoretical and experimental work has proven that local ferromagnetism can be obtained in transition-metal-doped perovskite niobates [15][16][17]. Specifically, as a prototype of an A-site atom with an oxidation state of +2, BaNbO 3 has shown great potential as a room temperature DMS, showing that the introduction of oxygen defects, modulation of the electric field and Co doping with transition metals can be achieved; however, its M sat is limited to approximately 10 −2 emu g −1 [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Increased room temperature ferromagnetism in Co-doped tetrahedral perovskite niobates

Zhou

et al. 2021

R. Soc. open sci.

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Dilute magnetic semiconductors (DMSs), such as (In, Mn)As and (Ga, Mn)As prototypes, are limited to III–V semiconductors with Curie temperatures ( T c ) far from room temperature, thereby hindering their wide application. Here, one kind of DMS based on perovskite niobates is reported. BaM x Nb (1− x ) O 3− δ ( M = Fe, Co) powders are prepared by the composite-hydroxide-mediated method. The addition of M elements endows BaM x Nb (1− x ) O 3− δ with local ferromagnetism. The tetragonal BaCo x Nb (1− x ) O 3− δ nanocrystals can be obtained by Co doping, which shows strong saturation magnetization ( M sat ) of 2.22 emu g −1 , a remnant magnetization ( M r ) of 0.084 emu g −1 and a small coercive field ( H c ) of 167.02 Oe at room temperature. The ab initio calculations indicate that Co doping could lead to a 64% local spin polarization at the Fermi level ( E F ) with net spin DOS of 0.89 electrons eV −1 , this result shows the possibility of maintaining strong ferromagnetism at room temperature. In addition, the trade-off effect between the defect band absorption and ferromagnetic properties of BaM x Nb (1− x ) O 3− δ is verified experimentally and theoretically.

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Effects of Fe substitution by Nb on physical properties of BaFeO3: A DFT+U study

Cited by 12 publications

References 61 publications

Strain induced Jahn-Teller distortions in BaFeO3 : A first-principles study

Strain induced Jahn-Teller distortions in BaFeO3 : A first-principles study

Surface restructuring of a perovskite-type air electrode for reversible protonic ceramic electrochemical cells

Increased room temperature ferromagnetism in Co-doped tetrahedral perovskite niobates

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