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Properties of BiFeO_{3} under an electric field are simulated using an ab initio-based approach. Complex paths and anomalous phenomena occur, depending on the direction of the field. Examples of such phenomena are the rotations of the polarization and of the axis about which the oxygen octahedra tilt; isostructural transitions; disappearance and reappearance of the tilting of the oxygen octahedra; and reentrance into specific crystallographic classes.The magnetic order parameter is not always perpendicular to the polarization, especially when the tilting of the oxygen octahedra disappears. The governing "rule" is that the magnetic order parameter remains orthogonal to the axis about which the oxygen octahedra tilt.
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http://dx.doi.org/10.1103/PhysRevLett.103.047204 | DOI Listing |
Nanomaterials (Basel)
August 2025
Centro de Excelencia en Materiales Avanzados-Nanotecnología, LEITAT Chile, Santiago 7500724, Chile.
In this study, a green hydrothermal synthesis method was employed to produce and /β-MnO nanostructures using EET-50, an organic extract obtained from a by-product of Carménère wine production. The biomolecules in EET-50 acted as reducing agents due to their electron-donating functional groups, enabling nanostructure formation without the need for additional chemical reductants. Morphological characterization by SEM revealed that a KMnO/EET-50 mass ratio of 3:1 led to the synthesis of nano-octahedra alongside rod-like structures, with shorter reaction times favoring the development of isolated nano-octahedra ranging from 100 nm to 170 nm.
View Article and Find Full Text PDFCommun Mater
August 2025
Department of Materials Engineering, KU Leuven, Leuven, Belgium.
Oxygen loss is a common defect type in perovskites which is caused by a low oxygen background pressure during growth. BaBiO thin films are grown by molecular beam epitaxy on SrTiO-buffered Si(001) substrates. Although activated oxygen is supplied during growth, large amount of oxygen vacancies is created in the thin film depending on the cooldown process.
View Article and Find Full Text PDFAdv Mater
August 2025
Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
Oxygen octahedra tilt, an important knob to tune properties of perovskite oxides and their derivatives, determines the coupling patterns and emergent states. Conventional methods, such as strain and doping, are primarily employed to modulate the magnitude of the octahedra tilt. The switching of the tilt, however, is challenging due to the intrinsic interlocked coupling.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu Cho, Sakyo, Kyoto 606-8501, Japan.
Iridium oxide is a benchmark catalyst for anodic oxygen evolution reactions due to its high activity and durability. However, debates persist regarding the short lifespan of reaction intermediates and whether amorphous phases exhibit higher activity in comparison to crystalline ones. Herein, we examined IrO catalysts with different degrees of crystallinity (SA3.
View Article and Find Full Text PDFJ Hazard Mater
September 2025
School of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, PR China; Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing & Finishing, Wuhan Textile University, Wuhan 430200, PR China. Electronic address:
The development of efficient and eco-friendly solid catalysts with strong Lewis acid sites for permanganate (KMnO) activation is highly desired for pollutant removal. In this study, the oxygen vacancy (O) content of cryptomelane-type manganese oxide, was modulated by Ce doping to promote its Lewis acidity. The findings show that incorporating Ce into the framework of MnO octahedra inhibits the growth of the catalyst to form a completely amorphous structure, with the increase of O ratio, especially bulk O content.
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