The basic structure of alpha-LiFeO2, lithium iron oxide, is a cubic NaCl-type structure with a lattice constant of 0.42 nm; some short-range ordering characterized by octahedral clusters exists. The local structure of the short-range ordering was investigated by transmission electron microscopy and electron diffraction. A new short-range ordering structure was found in local areas. The local structure has a cubic lattice with a doubled lattice constant. The occupation factors of cations on Wyckoff sites 4(a) and 4(b) are different from those on 24(d) sites, but the stoichiometric composition in cubic clusters is the same as the macroscopic composition. The number of pairs in which iron cations exist in nearest-neighbor sites and next nearest-neighbor sites is reduced in the structure. This means that a magnetic interaction between the iron cations is reduced by cation ordering even without spin ordering at room temperature.
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http://dx.doi.org/10.1107/S0108768104023456 | DOI Listing |
Int J Mol Sci
January 2025
Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA.
We incorporated Espaloma forcefield parameterization into MoSDeF tools for performing molecular dynamics simulations of organic molecules with HOOMD-Blue. We compared equilibrium morphologies predicted for perylene and poly-3-hexylthiophene (P3HT) with the ESP-UA forcefield in the present work against prior work using the OPLS-UA forcefield. We found that, after resolving the chemical ambiguities in molecular topologies, ESP-UA is similar to GAFF.
View Article and Find Full Text PDFFoods
January 2025
Department of Food Science and Biotechnology, National Chung Hsing University, 145 Xingda Road, Taichung 40227, Taiwan.
This study investigates the effect of ultrasonic-assisted preparation on the structural and physicochemical properties of water caltrop starch-palmitic acid complexes as a function of ultrasound intensity and treatment time. All samples exhibited the characteristic birefringence of starch-lipid complexes under the polarized microscope, and flake-like and irregular structure under scanning electron microscope (SEM), indicating the formation of complexes through ultrasonic-assisted preparation. X-ray diffraction pattern further confirmed the transition from the original A-type structure for native starch to V-type structure for starch-lipid complexes, and the relative crystallinity of starch-lipid complexes increased as the ultrasound intensity and treatment time increased.
View Article and Find Full Text PDFInorg Chem
January 2025
CNRS, University of Bordeaux, Bordeaux INP, ICMCB UMR CNRS 5026, F-33600 Pessac ,France.
The diaspore-type crystalline structure is historically well-known in mineralogy, but it has also been widely studied for various applications in the field of catalysis, electrocatalysis, and batteries. However, once two anions of similar ionic size but different electronegativity, such as F and O or more precisely OH, are combined, the knowledge of the location of these two anions is of paramount importance to understand the chemical properties in relation with the generation of hydrogen bonds. Coprecipitation and hydrothermal routes were used to prepare hydroxide-fluorides that crystallize all in an orthorhombic structure with four formula units per cell.
View Article and Find Full Text PDFScience
January 2025
Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano), Hysitron Applied Research Center in China (HARCC) and Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
Higher strength and higher ductility are desirable for structural materials. However, ultrastrong alloys inevitably show decreased strain-hardening capacity, limiting their uniform elongation. We present a supranano (<10 nanometers) and short-range ordering design for grain interiors and grain boundary regions, respectively, in fine-grained alloys based on vanadium, cobalt, and nickel, with additions of tungsten, copper, aluminum, and boron.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Innovation Institute of Carbon Neutrality, International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
Nowadays, it is challenging to achieve SO-tolerant environmental catalysis for NO reduction because of the thermodynamically favorable transformation of reactive sites to inactive sulfate species in the presence of SO. Herein, we achieve enhanced low-temperature SO-tolerant NO reduction by manipulating the dynamic coordination environment of active sites. Engineered by coordination chemistry, SiO-CeO composite oxides with a short-range ordered Ce-O-Si structure were elaborately constructed on a TiO support.
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