Temperature-dependent (57)Fe Mössbauer spectroscopy (5-723 K) and neutron diffraction (2-290 K) measurements are carried out on polycrystalline magnetoelectric GaFeO(3). From the neutron diffraction data, evidence for the magnetostriction and increased disorder at Fe sites close to the ferrimagnetic Curie transition temperature (T(C)) is observed. From the Mössbauer data, it is observed that the Lamb-Mössbauer factor as a function of temperature f(T), which is related to the integral over the first Brillouin zone of the phonon spectrum, shows a unequivocal variation at the T(C). The observations are discussed in terms of spin-phonon coupling. The observed average hyperfine fields from (57)Fe Mössbauer spectra match with the bulk magnetization data. A critical exponent (β) of 0.38 ± 0.02 and a Debye temperature (θ(D)) of ~350 K is estimated from the (57)Fe Mössbauer data.
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http://dx.doi.org/10.1088/0953-8984/24/37/376001 | DOI Listing |
Nanoscale
January 2025
J. Heyrovský Institute of Physical Chemistry, Czech Acad. Sci., Dolejškova 3, CZ-18200, Prague 8, Czech Republic.
Compositionally complex doping of spinel oxides toward high-entropy oxides is expected to enhance their electrochemical performance substantially. We successfully prepared high-entropy compounds, the oxide (ZnMgCoCu)FeO (HEOFe), lithiated oxyfluoride Li(ZnMgCoCu)FeOF (LiHEOFeF), and lithiated oxychloride Li(ZnMgCoCu)FeOCl (LiHEOFeCl) with a spinel-based cubic structure by ball milling and subsequent heat treatment. The products exhibit particles with sizes from 50 to 200 nm with a homogeneous atomic distribution.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, CHN, ETH Zürich, 8092 Zürich, Switzerland.
Coastal sediments are a key contributor to oceanic phosphorus (P) removal, impacting P bioavailability and primary productivity. Vivianite, an Fe(II)-phosphate mineral, can be a major P sink in nonsulfidic, reducing coastal sediments. Despite its importance, vivianite formation processes in sediments remain poorly understood.
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States.
Investigating material properties is essential to assessing their application potential. While computational methods allow for a fast prediction of the material structure and properties, experimental validation is essential to determining the ultimate material potential. Herein, we report the synthesis and experimental magnetic properties of three previously reported Kagome compounds in the Li-Fe-Ge system.
View Article and Find Full Text PDFInorg Chem
December 2024
Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe 76131, Germany.
J Inorg Biochem
March 2025
Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States. Electronic address:
The synthesis and characterization of a new ligand, 1-(bis(pyridin-2-ylmethyl) amino)-2-methylpropane-2-thiolate (BPAS) and its nonheme iron complex, Fe(BPAS)Br (1), is reported. Reaction of 1 with O at -20 °C generates a high-spin iron(III)-hydroxide complex, [Fe(OH)(BPAS)(Br)] (2), that was characterized by UV-vis, Fe Mössbauer, and electron paramagnetic resonance (EPR) spectroscopies, and electrospray ionization mass spectrometry (ESI-MS). Density functional theory (DFT) calculations were employed to support the spectroscopic assignments.
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