The perovskite structure of manganate yields a series of intriguing physical properties. Based on the results of first-principles calculations, strontium manganate appears to undergo a magnetic phase transition and a metal-insulator transition-from antiferromagnetic insulator to ferromagnetic metal and then to ferromagnetic insulator-under isotropic volume expansion combined with oxygen octahedral distortions. Interestingly, the results show that increasing the Mn-O bond length and adding rotation of the oxygen octahedra can soften the breathing distortion and account for the insulator phase. We further build a simple model to explain such transitions. Due to electron transfer and the favoring of a hole state of ligandorbitals, the electron state transfer from2(t2g3)to2(eg1+t2g2)and then tot2g3eg1+(t2g3L̲1). Such rearrangement of charges is responsible for the transitions of its magnetic order and electronic structure. Furthermore, we calculate spin susceptibility under the bare conditions and random phase approximation. The magnetic order of the intermediate metal state of itinerant electrons behaves as a ferromagnetic.
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March 2024
Henan Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng, 475004, China.
The search for high-performance and low-cost electrocatalysts in acid conditions still remains a challenging target. Herein, iridium (Ir) doped strontium manganate (named as Ir -SMO) is proposed as an efficient and durable low-iridium electrocatalyst for water oxidation in acidic media. The Ir -SMO with 75% less iridium in comparison to that of iridium dioxide (IrO ) exhibits excellent performance for oxygen evolution reaction (OER), which is even better than most of the iridium-based oxide electrocatalysts.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
December 2022
School of Mathematics and Physics, Queen's University Belfast, BelfastBT7 1NN, Northern Ireland, United Kingdom.
The role of local chemical environments in the electron energy loss spectra of complex multiferroic oxides was studied using computational and experimental techniques. The evolution of the O K-edge across an interface between bismuth ferrite (BFO) and lanthanum strontium manganate (LSMO) was considered through spectral averaging over crystallographically equivalent positions to capture the periodicity of the local O environments. Computational techniques were used to investigate the contribution of individual atomic environments to the overall spectrum, and the role of doping and strain was considered.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2021
Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing 100049, People's Republic of China.
The perovskite structure of manganate yields a series of intriguing physical properties. Based on the results of first-principles calculations, strontium manganate appears to undergo a magnetic phase transition and a metal-insulator transition-from antiferromagnetic insulator to ferromagnetic metal and then to ferromagnetic insulator-under isotropic volume expansion combined with oxygen octahedral distortions. Interestingly, the results show that increasing the Mn-O bond length and adding rotation of the oxygen octahedra can soften the breathing distortion and account for the insulator phase.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2020
Department of Chemistry, University College London, WC1H 0AJ, London, UK.
One of the main challenges facing solid oxide fuel cell (SOFC) technology is the need to develop materials capable of functioning at intermediate temperatures (500-800 °C), thereby reducing the costs associated with SOFCs. Here, Sm0.75A0.
View Article and Find Full Text PDFJ Hazard Mater
April 2019
Institut Charles Gerhardt de Montpellier, CNRS UMR 5253, Univ Montpellier, CNRS, ENSCM, Place Eugène Bataillon, 34095, Montpellier cedex 5, France. Electronic address:
An alternative microwave-assisted hydrothermal route for the preparation of manganate nanoflowers under basic conditions has been proposed in view of potential uses in selective retention of strontium from multicomponent aqueous streams. Based on the combination of such characterization techniques as Scanning and Transmission Electronic Microscopy, X-ray photoelectron spectroscopy, and X-ray Diffraction, as well as taking advantage of the computer-aided structure simulation, homogeneous nanoflower morphology possessing a layered structure and K compensating cations was evidenced as corresponding to the KMnO chemical formula. The nanoflower sample was subsequently tested for the selective adsorption of strontium and cesium by measuring the individual adsorption isotherms from single-solute and multicomponent aqueous solutions.
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