On the superconducting state in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si0022.gif" overflow="scroll"><mml:mrow><mml:msub><mml:mrow><mml:mi>Ba</mml:mi></mml:mrow><mml:mrow><mml:mn>0.6</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi mathvariant="normal">K</mml:mi></mml:mrow><mml:mrow><mml:mn>0.4</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>BiO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> perovskite oxide

Szczęśniak, D.; Kaczmarek, Adam Z.; Drzazga, E.A.; Szewczyk, K. A.; Szczȩśniak, R.

doi:10.1016/j.physb.2017.10.127

Cited by 7 publications

(8 citation statements)

References 36 publications

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“…These results allow to determine the desired µ c value, which is equal to 0.14 and 0.18 for the x = 0.5 and x = 0.7 case, respectively. We observe, that the predicted µ c values are relatively high comparing to the typical phononmediated superconductors, however they are very close to the previously predicted estimates for the optimally doped BKBO with x = 0.6 [20]. Similarly to [20], the observed high values of the Coulomb pseudopotential does not follow the Morel-Anderson model [34], what can be explained by the small influence of the retardation effects on its value, as suggested within the approach of Bauer et al [35].…”

Section: Numerical Resultssupporting

confidence: 88%

“…The Ba x K 1−x BiO 3 (BKBO) perovskite oxide constitutes one of the most extensively analyzed superconductors, up to date [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The reason for such a considerable interest in this compound stems from the relatively high critical temperature (T c ) values which can be obtained in this compound [1,8,19], as well as the non-conventional behavior of its other thermodynamic properties [4,7,12,20]. In this context, considerable attention was given to the understanding of pairing mechanism in the discussed material, which appeared to be a formidable challenge for both theory and experiment.…”

Section: Introductionmentioning

confidence: 99%

“…In favor of the latter predictions, recently we have accounted for the phonon-mediated character of the superconducting phase induced in the optimally doped BKBO i.e when x = 0.6 [20]. The recalled analysis was conducted within the Eliashberg formalism [22] -a generalization of the Bardeen-Cooper-Schrieffer (BCS) theory [23,24] -to predict the most important thermodynamic properties that describe the superconducting state.…”

Section: Introductionmentioning

confidence: 99%

“…In this context, herein we use the same methodology as in [20] and investigate behavior of the superconducting phase in BKBO at the boundaries of its existence. In particular, two mentioned doping cases (x = 0.7 and x = 0.5) are discussed in the framework of the isotropic Eliashberg equations, assuming that critical temperature values are equal to the experimental data presented in [8,19].…”

Section: Introductionmentioning

confidence: 99%

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Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Szczȩśniak,

Kaczmarek,

Szczȩśniak

et al. 2018

Preprint

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In the present study, we investigate the thermodynamic properties of the BaxK1−xBiO3 (BKBO) superconductor in the under-(x = 0.5) and over-doped (x = 0.7) regime, within the framework of the Migdal-Eliashberg formalism. The analysis is conducted to verify that the electron-phonon pairing mechanism is responsible for the induction of the superconducting phase in the mentioned compound.In particular, we show that BKBO is characterized by the relatively high critical value of the Coulomb pseudopotential, which changes with doping level and does not follow the Morel-Anderson model. In what follows, the corresponding superconducting band gap size and related dimensionless ratio are estimated to increase with the doping, in agreement with the experimental predictions. Moreover the effective mass of electrons is found to take on high values in the entire doping and temperature region. Finally, the characteristic dimensionless ratios for the superconducting band gap, the critical magnetic field and the specific heat for the superconducting state are predicted to exceed the limits set within the Bardeen-Cooper-Schrieffer theory, suggesting pivotal role of the strong-coupling and retardation effects in the analyzed compound. Presented results supplement our previous investigations and account for the strong-coupling phonon-mediated character of the superconducting phase in BKBO at any doping level.

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Section: Numerical Resultssupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Szczȩśniak,

Kaczmarek,

Szczȩśniak

et al. 2018

Preprint

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“…where λ αβ denotes the electron-phonon coupling con- stant, which is defined in the matrix form as follows [24]: (4) The Eliashberg equations (1) and (2) are numerically solved by using the modified numerical procedures initially developed for the isotropic materials [25][26][27][28][29] and later adopted to three-band CaC 6 superconductor [12]. In this context, the input parameters for the calculations are the critical temperature T C = 11.5 K and the corresponding elements of the Coulomb pseudopotential (µ ⋆ αβ ) matrix [24]: 4) and (5) are arranged with respect to the assumed band indices.…”

Section: Theoretical Modelmentioning

confidence: 99%

Revealing the anisotropy effects on the critical magnetic field in CaC6 superconductor

2019

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The calcium intercalated graphite (CaC6) is considered to be a representative material of the graphite intercalated superconductors, which exhibits sizable anisotropy of the Fermi surface (FS). Herein, the influence of the FS anisotropy on the critical magnetic field (HC) in CaC6 superconductor is comprehensively analyzed within the Migdal-Eliashberg (M-E) formalism. To precisely account for the mentioned anisotropy effects, the analysis is conducted in the framework of the six-band approximation, hitherto not employed for calculations of the HC function in CaC6 material. For convenience, the obtained results are compared with the available one-and three-band estimates reported by using the M-E theory. A notable signatures of the increased number of bands are observed for the temperature dependent HC functions. In particular, the HC function decreases at T=0 K as the number of the considered bands is higher. Moreover, it is argued that the sixband formalism yields the most physically relevant shape of the HC function among all considered approximations. Therefore, the six-band model introduces not only quantitative but also qualitative changes to the results, in comparison to the other discussed FS approximations. This observation supports postulate that the six-band model constitutes minimal structure for FS of CaC6, but also magnify importance of anisotropy effects for the critical magnetic field calculations.

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Account of Structural, Theoretical, and Photovoltaic Properties of ABO₃ Oxide Perovskites Photoanode‐Based Dye‐Sensitized Solar Cells

et al. 2021

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The quality of human life in the modern era seems to be highly reliable on the technology advancements and energy consumption. [1] Globally, around 85% of the energy depends on nonrenewable sources which may extinct within next few years. [2] In this context, solar cells in specifically dye-sensitized solar cells (DSSCs), which come under thin-filmbased third-generation solar cells, are considered to play a vital role of fulfilling the future energy needs by means of its proficient energy conversion potential, in addition to its lightweight, low-cost, reliable efficiency, multicolor options, and feasible for both indoor and outdoor applications. It is one of the most promising energy conversion devices from its technological discovery of early 1990s by Brain O'Regan and Michael Gratzel [3,4] In general, the working of DSSC depends on five major components, namely, 1) substrate, 2) semiconductor nanolayer, 3) the sensitizer, 3) redox electrolyte, and 5) counter electrode. The schematic representation of a typical DSSC with components is shown in Figure 1.Initially, the photosensitizer (dye) of the DSSC usually in its ground state and the illumination of light over the DSSC excite the ground state dye molecules from highest occupied molecular orbital (HOMO) level to the lowest unoccupied molecular orbital (LUMO) level (1), and then the electron from the LUMO level jumps over the conduction band of the semiconductor in 150 ps (2) and reaches the TCO. The holes produced during the excitation of dye molecules are scavenged by the electrons from the redox electrolyte (4) in 0.5 μs. The electrons reached the TCO then move to the cathode through the external circuit and power up the electrical load. Finally, the oxidized electrolyte gets reduced at the cathode (5) in 10 μs. [5,6] Besides these carrier-transport processes, some adverse reactions like nonradiative carrier-recombination paths will occur that desperately reduces the overall device performance. [7] Such unfavorable reactions are follows: nonradiative decay of immediate excitation of dye molecule to its ground state occurs in ns (6), plausible recombination of the electrons from the conduction band of the semiconductor material to the ground state of dye molecule occurs in ms (7), and to the electrolyte occurs in 100 ns to 1 ms (8), respectively. [8] The substrate for the photoanode and cathode is the most important component. Apart from this metal foil or polymeric film, transparent conductive oxide (TCO)-coated transparent glass substrate, such as fluorine-doped tin dioxide (FTO) or

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On the superconducting state in Ba0.6K0.4BiO3 perovskite oxide

Cited by 7 publications

References 36 publications

Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Revealing the anisotropy effects on the critical magnetic field in CaC6 superconductor

Account of Structural, Theoretical, and Photovoltaic Properties of ABO₃ Oxide Perovskites Photoanode‐Based Dye‐Sensitized Solar Cells

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On the superconducting state in Ba0.6K0.4BiO3 perovskite oxide

Cited by 7 publications

References 36 publications

Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Superconducting properties of under- and over-doped Ba$_{x}$K$_{1-x}$BiO$_{3}$ perovskite oxide

Revealing the anisotropy effects on the critical magnetic field in CaC6 superconductor

Account of Structural, Theoretical, and Photovoltaic Properties of ABO3 Oxide Perovskites Photoanode‐Based Dye‐Sensitized Solar Cells

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Account of Structural, Theoretical, and Photovoltaic Properties of ABO₃ Oxide Perovskites Photoanode‐Based Dye‐Sensitized Solar Cells