Super‐Exchange Interaction Induced Overall Optimization in Ferromagnetic Perovskite Oxides Enables Ultrafast Water Oxidation

Small ◽  
2019 ◽  
Vol 15 (39) ◽  
pp. 1903120 ◽  
Author(s):  
Jie Dai ◽  
Yinlong Zhu ◽  
Yichun Yin ◽  
Hassan A. Tahini ◽  
Daqin Guan ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Water Oxidation ◽  
Perovskite Oxides ◽  
Super Exchange Interaction

Linking surface chemistry to photovoltage in Sr-substituted LaFeO3 for water oxidation

2018 ◽  
Vol 6 (44) ◽  
pp. 22170-22178 ◽  
Author(s):  
Kelsey A. Stoerzinger ◽  
Le Wang ◽  
Yifan Ye ◽  
Mark Bowden ◽  
Ethan J. Crumlin ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Water Oxidation ◽  
Perovskite Oxides

Perovskite oxides are promising materials for photoabsorbers and electrocatalysts for solar-driven water oxidation.

scholarly journals An aqueous preoxidation method for monolithic perovskite electrocatalysts with enhanced water oxidation performance

2016 ◽  
Vol 2 (10) ◽  
pp. e1600495 ◽  
Author(s):  
Bo-Quan Li ◽  
Cheng Tang ◽  
Hao-Fan Wang ◽  
Xiao-Lin Zhu ◽  
Qiang Zhang
Keyword(s):  
Water Oxidation ◽  
Fenton Reaction ◽  
Nickel Foam ◽  
Three Dimensional ◽  
Active Phase ◽  
Perovskite Oxides ◽  
High Temperature Annealing ◽  
Current Collectors ◽  
Oxidation Performance

Perovskite oxides with poor conductivity call for three-dimensional (3D) conductive scaffolds to demonstrate their superb reactivities for oxygen evolution reaction (OER). However, perovskite formation usually requires high-temperature annealing at 600° to 900°C in air, under which most of the used conductive frameworks (for example, carbon and metal current collectors) are reductive and cannot survive. We propose a preoxidization coupled electrodeposition strategy in which Co2+ is preoxidized to Co3+ through cobalt Fenton reaction in aqueous solution, whereas the reductive nickel framework is well maintained during the sequential annealing under nonoxidative atmosphere. The in situ–generated Co3+ is inherited into oxidized perovskites deposited on 3D nickel foam, rendering the monolithic perovskite electrocatalysts with extraordinary OER performance with an ultralow overpotential of 350 mV required for 10 mA cm−2, a very small Tafel slope of 59 mV dec−1, and superb stability in 0.10 M KOH. Therefore, we inaugurate a unique strategy for in situ hybridization of oxidative active phase with reductive framework, affording superb reactivity of perovskite electrocatalyst for efficient water oxidation.

Enhancement in A-B super-exchange interaction with Mn substitution in Mg-Zn ferrites as a heating source in hyperthermia applications

2017 ◽  
Vol 43 (16) ◽  
pp. 13661-13669 ◽  
Author(s):  
Rohit Sharma ◽  
Prashant Thakur ◽  
Manoj Kumar ◽  
P.B. Barman ◽  
Pankaj Sharma ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Heating Source ◽  
Mn Substitution ◽  
Super Exchange Interaction

Pushing the Limits of Metastability in Semiconducting Perovskite Oxides for Visible-Light-Driven Water Oxidation

2020 ◽  
Vol 32 (7) ◽  
pp. 3054-3064
Author(s):  
Shaun O’Donnell ◽  
Ching-Chang Chung ◽  
Abigail Carbone ◽  
Rachel Broughton ◽  
Jacob L. Jones ◽  
...  
Keyword(s):  
Visible Light ◽  
Water Oxidation ◽  
Perovskite Oxides ◽  
Visible Light Driven

scholarly journals Superconductivity Mechanism in the Modulated Quantum Well of YBCO Structure

2014 ◽  
Vol 70 (a1) ◽  
pp. C620-C620
Author(s):  
Tri Nguyen Van
Keyword(s):  
Quantum Well ◽  
Exchange Interaction ◽  
Pauli Principle ◽  
Metallic Phase ◽  
Spin Coupling ◽  
Free Electrons ◽  
Quantum Electron ◽  
De Broglie Wavelength ◽  
Super Exchange Interaction

The modulated structure by high pressure and the superconductivity of YBCO compounds have been revealed over two decades [1]. However, their nature & mechanism are not yet sufficiently known. Continuing the achieved results [2-3], the present paper aims to evidence how the Quantum Electron-Magnetic Phenomenon, namely the Super-Exchange Interaction of the "active electrons", i.e. the hybridized odd electrons from the Cu ions in the Cu-Y-Cu nanolayer as a Nanowaveguide (NWG), conditions the Superconductivity of YBCO. The 1st key: The nanostructure is of Quantum nature. The active electrons behavior as the Quasi-Free Electrons (QFEs) waving in the Quantum Well (NWG), where they can be favored to a strong Super-Exchange Interaction. Thereby, two types of the spin coupled pairs can be spontaneously formed in the NWG, where just the singlet pairs will play the role of the superconducting Cooper pairs. For studying these nanoeffects, ESR can offer an especially efficacious contribution. The 2nd key: On the basis of the consequences of the Pauli principle, the singlet pair only persists if its QFE cloud overlapping path length L = nλ/2, where λ is the de Broglie wavelength of QFE conditioned by the Nanodimension of the NWG (Fig.1, left). This electron waving status corresponds to an ideal metallic phase occurring in the NWG. The 3rd key: The spin coupling brings about a temperature depending Spin Gap of the QFEs in the NWG. Just this Spin Gaps causes the superconductivity with the phase transition characteristics (Fig.1, right) that exactly and surprisingly correspond with the experimental.

Structure and super-exchange interaction in a dinuclear iron(III) complex

2000 ◽  
Vol 516 (1) ◽  
pp. 43-47 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
I. Svoboda ◽  
H. Fuess
Keyword(s):  
Exchange Interaction ◽  
Dinuclear Iron ◽  
Super Exchange Interaction

Oxygen defect engineering in double perovskite oxides for effective water oxidation

2020 ◽  
Vol 8 (21) ◽  
pp. 10957-10965 ◽  
Author(s):  
Yunmin Zhu ◽  
Xiao Zhong ◽  
Shiguang Jin ◽  
Haijun Chen ◽  
Zuyun He ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Oxygen Vacancies ◽  
Double Perovskite ◽  
Perovskite Oxides ◽  
Oxygen Defect ◽  
Defect Engineering ◽  
Effective Water

Generating oxygen vacancies in PrBa0.5Sr0.5Co1.5Fe0.5O5+δvia plasma treatment for strongly boosted oxygen evolution reaction activity.

Materials Design for the Low-Resistivity in p-Type ZnO and Transparent Ferromagnet With Transition Metal Atom Doped ZnO: Prediction vs. Experiment

2000 ◽  
Vol 623 ◽  
Author(s):  
K. Sato ◽  
H. Katayama-Yoshida ◽  
T. Yamamoto
Keyword(s):  
Exchange Interaction ◽  
Control Method ◽  
Double Exchange ◽  
Ferromagnetic State ◽  
Materials Design ◽  
Hole Doping ◽  
Double Exchange Interaction ◽  
Low Resistivity ◽  
Valence Control ◽  
Super Exchange Interaction

AbstractWe propose a new valence control method of codoping with doping Ga (or In, Al) donor and N acceptor at the same time for the fabrication of a low-resistivity p-type ZnO based upon the ab initio calculation. We compare our predicted materials design to fabricate a low resistivity p-type ZnO with the recent successful codoping. Based upon the success in the valence control of ZnO, we propose a materials design to fabricate the ferromagnetic Mn-doped p-type ZnO upon codoping. It is shown that the anti-ferromagnetic state is more stable than the ferromagnetic ones due to the anti-ferromagnetic super-exchange interaction, if we have no mobile holes. Upon codoping with the mobile holes, it is shown that the ferromagnetic state becomes more stable than the anti-ferromagnetic ones due to the ferromagnetic double-exchange interaction. However, it is shown that the anti-ferromagnetic state is more stable upon electron doping due to the anti-ferromagnetic super-exchange interaction. We calculate the chemical trends of the magnetic state in V-, Cr-, Fe-, Co-, and Ni-doped (25 at%) in ZnO, and predict that all of these materials show the ferromagnetic ground states without electron and hole doping.

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