Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Local A-Site Layering in Rare-Earth Orthochromite Perovskites by Solution Synthesis.

ABSTRACT: Cation size effects were examined in the mixed A-site perovskites La_0.5 Sm_0.5 CrO₃ and La_0.5 Tb_0.5 CrO₃ prepared through both hydrothermal and solid-state methods. Atomically resolved electron energy loss spectroscopy (EELS) in the transmission electron microscope shows that while the La and Sm cations are randomly distributed, increased cation-radius variance in La_0.5 Tb_0.5 CrO₃ results in regions of localised La and Tb layers, an atomic arrangement exclusive to the hydrothermally prepared material. Solid-state preparation gives lower homogeneity resulting in separate nanoscale regions rich in La³⁺ and Tb³⁺ . The A-site layering in hydrothermal La_0.5 Tb_0.5 CrO₃ is randomised upon annealing at high temperature, resulting in magnetic behaviour that is dependent on synthesis route.

SUBMITTER: Daniels LM

PROVIDER: S-EPMC5216904 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Local A-Site Layering in Rare-Earth Orthochromite Perovskites by Solution Synthesis.

Daniels Luke M LM Kashtiban Reza J RJ Kepaptsoglou Demie D Ramasse Quentin M QM Sloan Jeremy J Walton Richard I RI Walton Richard I RI

Chemistry (Weinheim an der Bergstrasse, Germany) 20161103 51

Cation size effects were examined in the mixed A-site perovskites La0.5 Sm0.5 CrO3 and La0.5 Tb0.5 CrO3 prepared through both hydrothermal and solid-state methods. Atomically resolved electron energy loss spectroscopy (EELS) in the transmission electron microscope shows that while the La and Sm cations are randomly distributed, increased cation-radius variance in La0.5 Tb0.5 CrO3 results in regions ...[more]

PMID: 27727487

Similar Datasets

Synthesis, dielectric, magnetic, and photoluminescence properties of two new hybrid rare-earth double perovskites.

Project description:Two new organic-inorganic hybrid double perovskites (R3HQ)4CsSm(NO3)8 (1) (R3HQ = (R)-(-)-3-quinuclidinol) and (R3HQ)4CsEu(NO3)8 (2) were synthesized and characterized. Compounds 1 and 2 exhibit obvious phase transitions at 379 and 375 K, respectively, confirmed by differential scanning calorimetry (DSC) and variable temperature powder X-ray diffraction. The rapid switching between high- and low-dielectric states makes it a typical dielectric material with a switchable dielectric constant for thermal stimulus response. Furthermore, 1 and 2 show attractive photoluminescence and paramagnetic behavior, and the fluorescence quantum yield of 2 reached 14.6%. These results show that compounds 1 and 2 can be used as excellent candidates for multifunctional intelligent materials, which also provides a new way for development of multifunctional materials.

| S-EPMC9389020 | biostudies-literature

Multiple Energy Transfer Channels in Rare Earth Doped Multi-Exciton Emissive Perovskites.

Project description:Revealing the energy transfer (ET) process from excitons to rare earth ions in halide perovskites has great guiding value for designing optoelectronic materials. Here, the multiple ET channels in multi-exciton emissive Sb3+ /Nd3+ co-doped Cs2 ZrCl6 are explored to comprehend the ET processes. Förster-Dexter ET theory reveals that the sensitizer concentration rather than the overlap integral of the spectra plays the leading function in the comparison of the ET efficiency among multiple ET channels from the host self-trapped excitons (STEs) and dopant triplet STEs to Nd3+ ions. Besides, Sb3+ /Nd3+ co-doped Cs2 ZrCl6 enables varied color delivery and has great potential as anti-counterfeiting material. Under X-ray irradiation, Sb3+ /Nd3+ co-doped Cs2 ZrCl6 presents a high light yield of ≈13300 photons MeV-1 and promising X-ray imaging ability. This work provides new insight for investigating the ET efficiency among multiple ET processes and presents great potentiality of multi-exciton emissive perovskites in the fields of anti-counterfeiting and X-ray imaging.

| S-EPMC10916588 | biostudies-literature

Magnetic Modes in Rare Earth Perovskites: A Magnetic-Field-Dependent Inelastic Light Scattering study.

Project description:Here, we report the presence of defect-related states with magnetic degrees of freedom in crystals of LaAlO3 and several other rare-earth based perovskite oxides using inelastic light scattering (Raman spectroscopy) at low temperatures in applied magnetic fields of up to 9 T. Some of these states are at about 140 meV above the valence band maximum while others are mid-gap states at about 2.3 eV. No magnetic impurity could be detected in LaAlO3 by Proton-Induced X-ray Emission Spectroscopy. We, therefore, attribute the angular momentum-like states in LaAlO3 to cationic/anionic vacancies or anti-site defects. Comparison with the other rare earth perovskites leads to the empirical rule that the magnetic-field-sensitive transitions require planes of heavy elements (e.g. lanthanum) and oxygen without any other light cations in the same plane. These magnetic degrees of freedom in rare earth perovskites with useful dielectric properties may be tunable by appropriate defect engineering for magneto-optic applications.

| S-EPMC5109287 | biostudies-literature

Rare-earth metal catalysts for high-pressure synthesis of rare diamonds.

Project description:The combination of the unique properties of diamond and the prospects for its high-technology applications urges the search for new solvents-catalysts for the synthesis of diamonds with rare and unusual properties. Here we report the synthesis of diamond from melts of 15 rare-earth metals (REM) at 7.8 GPa and 1800-2100 °C. The boundary conditions for diamond crystallization and the optimal parameters for single crystal diamond synthesis are determined. Depending on the REM catalyst, diamond crystallizes in the form of cube-octahedrons, octahedrons and specific crystals bound by tetragon-trioctahedron and trigon-trioctahedron faces. The synthesized diamonds are nitrogen-free and belong to the rare type II, indicating that the rare-earth metals act as both solvent-catalysts and nitrogen getters. It is found that the REM catalysts enable synthesis of diamond doped with group IV elements with formation of impurity-vacancy color centers, promising for the emerging quantum technologies. Our study demonstrates a new field of application of rare-earth metals.

| S-EPMC8055970 | biostudies-literature

Synthesis of rare-earth metal and rare-earth metal-fluoride nanoparticles in ionic liquids and propylene carbonate.

Project description:Decomposition of rare-earth tris(N,N'-diisopropyl-2-methylamidinato)metal(III) complexes [RE{MeC(N(iPr)2)}3] (RE(amd)3; RE = Pr(III), Gd(III), Er(III)) and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)europium(III) (Eu(dpm)3) induced by microwave heating in the ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIm][NTf2]) and in propylene carbonate (PC) yield oxide-free rare-earth metal nanoparticles (RE-NPs) in [BMIm][NTf2] and PC for RE = Pr, Gd and Er or rare-earth metal-fluoride nanoparticles (REF3-NPs) in the fluoride-donating IL [BMIm][BF4] for RE = Pr, Eu, Gd and Er. The crystalline phases and the absence of significant oxide impurities in RE-NPs and REF3-NPs were verified by powder X-ray diffraction (PXRD), selected area electron diffraction (SAED) and high-resolution X-ray photoelectron spectroscopy (XPS). The size distributions of the nanoparticles were determined by transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) to an average diameter of (11 ± 6) to (38 ± 17) nm for the REF3-NPs from [BMIm][BF4]. The RE-NPs from [BMIm][NTf2] or PC showed diameters of (1.5 ± 0.5) to (5 ± 1) nm. The characterization was completed by energy-dispersive X-ray spectroscopy (EDX).

| S-EPMC6036975 | biostudies-literature

Green Ultrasound-Assisted Synthesis of Rare-Earth-Based MOFs.

Project description:Rare-earth (RE)-based metal organic frameworks (MOFs) are quickly gaining popularity as flexible functional materials in a variety of technological fields. These MOFs are useful for more than just conventional uses like gas sensors and catalyst materials; in fact, they also show significant promise in emerging technologies including photovoltaics, optical, and biomedical applications. Using yttrium and europium as ionic host centres and dopants, respectively, and 1,3,5-benzenetricarboxylic acid (H3-BTC) as an organic linker, we describe a simple and green approach for the fabrication of RE-MOFs. Specifically, Y-BTCs and Eu-doped Y-BTCs MOFs have been synthesised in a single step using an eco-friendly method that makes use of ultrasound technology. To establish a correlation between the morphological and structural properties and reaction conditions, a range of distinct reaction periods has been employed for the synthetic processes. Detailed analyses of the synthesised samples through powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR) have confirmed the phase formation. Furthermore, thermal analyses such as thermogravimetric analysis (TGA) have been employed to evaluate the thermal stability and structural modifications of the Y-BTC and Eu-doped Y-BTC samples. Finally, the luminescent properties of the synthesised samples doped with Eu3+ have been assessed, providing an evaluation of their characteristics. As a proof of concept, an Eu-doped Y-BTC sample has been applied for the sensing of nitrobenzene as a molecule test of nitro derivatives.

| S-EPMC10458194 | biostudies-literature

Versatile synthesis of dendritic mesoporous rare earth-based nanoparticles.

Project description:Rare earth-based nanomaterials that have abundant optical, magnetic, and catalytic characteristics have many applications. The controllable introduction of mesoporous channels can further enhance its performance, such as exposing more active sites of rare earth and improving the loading capacity, yet remains a challenge. Here, we report a universal viscosity-mediated assembly strategy and successfully endowed rare earth-based nanoparticles with central divergent dendritic mesopores. More than 40 kinds of dendritic mesoporous rare earth-based (DM-REX) nanoparticles with desired composition (single or multiple rare earth elements, high-entropy compounds, etc.), particle diameter (80 to 500 nanometers), pore size (3 to 20 nanometers), phase (amorphous hydroxides, crystalline oxides, and fluorides), and architecture were synthesized. Theoretically, a DM-REX nanoparticle library with 393,213 kinds of possible combinations can be constructed on the basis of this versatile method, which provides a very broad platform for the application of rare earth-based nanomaterials with rational designed functions and structures.

| S-EPMC9337761 | biostudies-literature

Synthesis and Characterisation of Phosphino-Aryloxide Rare Earth Complexes.

Project description:A series of homoleptic rare earth (RE) complexes bearing phosphino-aryloxide ligands (1-RE, 2-La) has been prepared. The complexes have been characterised using multinuclear NMR and IR spectroscopy, X-ray crystallography and elemental analysis. Structural characterisation highlighted the different RE-P interactions as a result of differing Lewis acidity and ionic size across the series, hinting at the possibility of FLP-type activity. The potential reactivity of these complexes has been tested by reacting them with small molecules (H2, CO, CO2). A series of side-products (3-RE) has also been observed, isolated and characterised, featuring the incorporation of a phosphonium-aryloxide ligand.

| S-EPMC11643060 | biostudies-literature

Liquid-Phase Synthesis of Highly Reactive Rare-Earth Metal Nanoparticles.

Project description:The first liquid-phase synthesis of high-quality, small-sized rare-earth metal nanoparticles (1-3 nm)-ranging from lanthanum as one of the largest (187 pm) to scandium as the smallest (161 pm) rare-earth metal-is shown. Size, oxidation state, and reactivity of the nanoparticles are examined (e.g., electron microscopy, electron spectroscopy, X-ray absorption spectroscopy, selected reactions). Whereas the nanoparticles are highly reactive (e.g. in contact to air and water), they are chemically stable as THF suspensions and powders under inert conditions. The reactivity can be controlled to obtain inorganic and metal-organic compounds at room temperature.

| S-EPMC8361762 | biostudies-literature

Local coordination state of rare earth in eutectic scintillators for neutron detector applications.

Project description:Atomic distribution in phosphors for neutron detection has not been fully elucidated, although their ionization efficiency is strongly dependent on the state of the rare earth in the matrix. In this work, we examine optical properties of Eu-doped 80LiF-20CaF2 eutectics for neutron detector applications based on the Eu distribution. At low concentrations, aggregation of Eu cations is observed, whereas homogeneous atomic dispersion in the CaF2 layer, to substitute Ca(2+) ions, is observed in the eutectics at high concentrations. Eu LIII edge X-ray absorption fine structure (XAFS) analysis suggests that neutron responses do not depend on the amount of Eu(2+) ions. However, transparency, which depends on an ordered lamellar structure, is found to be important for a high light yield in neutron detection. The results confirm the effectiveness of the basic idea concerning the separation of radiation absorbers and activators in particle radiation scintillation and present potential for further improvement of novel bulk detectors.

| S-EPMC4544017 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data