Crystal structure and oxygen stoichiometry in , a potential lithium-battery cathode, vary with temperature, as observed samples quenched from different temperatures by situ diffraction thermogravimetry techniques. When prepared high pressure, this cation-ordered spinel is oxygen-stoichiometric, space group . Upon heating between 650 increasing deficiency occurs exclusively octahedra bonds, which induces volume increase of the 12d octahedra, reduction Mn shown X-ray absorption near-edge...

Controlling polymer thin-film morphology and crystallinity is crucial for a wide range of applications, particularly in organic electronic devices. In this work, the crystallization behavior model polymer, poly(ethylene oxide) (PEO), during spin-coating studied. PEO films were spun-cast from solvents possessing different polarities (chloroform, THF, methanol) probed via situ grazing incidence wide-angle X-ray scattering. The was found to follow solvent polarity order (where chloroform < THF...

Owing to its large capacity and high average potential, the structure reversible O-redox compensation mechanism of Na2 Mn3 O7 have recently been analyzed. However, fade low coulombic efficiency over multiple cycles also found be a problem, which result from oxygen evolution at charge voltages. Herein, Na0.44 MnO2 ⋅Na2 heterojunction primary nanosheets was prepared by sol-gel-assisted high-temperature sintering method. In nanodomain regions, close contact not only supplies multidimensional...

Abstract Disinfection residuals in drinking water protect quality and public heath by limiting planktonic microbial regrowth during distribution. However, we do not consider the consequences selective pressures of such on ubiquitous biofilms that persist vast internal surface area distribution systems. Using a full scale experimental facility, integrated analyses were applied to determine physical, chemical biological impacts different free chlorine regimes biofilm characteristics...

l-Pyroglutamic acid undergoes a phase transition, α → β, at ∼68 °C on heating, which is reversible with hysteresis depending the cooling rate, before melting ∼162 °C. On cooling, further α′, shows martensitic characteristics, occurs ∼ −140 The structural changes transitions were studied by variable temperature X-ray powder diffraction and Raman spectroscopy compared reports of single crystal structure determinations. Differences in spectra attributed to differences intermolecular N−H···O...

Nanocrystalline hydroxyapatite (nanoHA) is the main hard component of bone and has potential to be used promote osseointegration implants treat defects. Here, using active pharmaceutical ingredients (APIs) such as ibuprofen, we report on prospects combining nanoHA with biologically compounds improve clinical performance these treatments. In this study, designed investigated possibility API attachment surface crystals via formation a hydrogen-bonded complex. The mechanistic studies an...

The thermal behavior and phase transformations of the α β polymorphs l-glutamic acid were studied by differential scanning calorimetry, thermogravimetry, powder X-ray diffraction, gel permeation chromatography, mass spectrometry. Solid-state transformation to polymorph was observed at temperatures above 140 °C, together with, in sequence, cyclization pyroglutamic polymerization polyglutamic acid. resulting is a high molecular weight amorphous polymer, with glass transition temperature ∼20 °C.

The transformation on heating LiCoMnO4, with a spinel structure, to LiCoMnO3, cation-disordered rock salt accompanied by loss of 25% the oxygen, has been followed using combination diffraction, microscopy and spectroscopy techniques. does not proceed topotactic mechanism, even though phases have similar, cubic close-packed oxygen sublattice. Instead, passes through two stages involving, first, precipitation Li2MnO3, leaving behind Li-deficient, Co-rich non-stoichiometric and, second,...

Dense LaLuO 3 ceramics were prepared by the conventional solid‐state reaction route. Their room‐temperature (RT) crystal structure and microwave (MW) dielectric properties investigated. Rietveld refinements performed on X‐ray diffraction data show RT symmetry to be best described centrosymmetric orthorhombic Pnma space group [ a =6.01888 (9) Å, b =8.37489 (12) c =5.81841 (8) Z =4]. This assignment was further corroborated Raman spectroscopy analysis. At MW frequencies, sintered at 1525°C/4 h...

N-doped Li₃VO₄ of general formula Li_3+xVO_4−xN_x was prepared by solid state reaction Li₃N, V₂O₅ and either Li₂CO₃ or LiOH·H₂O.

For fusion to be realised as a safe, sustainable source of power, new structural materials need developed which can withstand high temperatures and the unique radiation environment. An attractive aspect is that no long-lived radioactive wastes will produced, but achieve this must comprise reduced activation elements. Compositionally complex alloys (CCAs) (also called entropy alloys, HEAs) are promising candidates for use in extreme environments, including fusion, few reported date have low...

LiCoMnO4−δ is one of the materials first reported as a 5 V cathode in prototype lithium batteries, but as-prepared material has residual 4 plateau addition to main plateau. A combination thermogravimetry on samples prepared under various conditions, high temperature X-ray powder diffraction and electrochemical testing, shows depend extent oxygen deficiency, δ, to, therefore, correlate with Mn3+ content. complex reaction sequence occurs upon loss, including formation oxygen-deficient spinel,...

The crystal structure of the diastereomeric salt 1 : L-ephedrine D-tartrate (1 LD, C10H16NO+·C4H5O6−) was determined from high-resolution synchrotron powder X-ray diffraction (PXRD) data using global optimization in direct space (parallel tempering) together with computational modelling to locate hydrogen positions and refined by Rietveld method. is monoclinic, group P21, a = 18.82810(3) Å, b 7.19429(2) c 5.73035(1) β 95.9613(1)°, V 772.006(3) Å3, Z 2. Computational prediction organic...

Lithium-ion diffusion mechanisms in the complex spinel Li2NiGe3O8 have been investigated using solid-state NMR, impedance, and muon spectroscopies. Partial occupancy of migratory interstitial 12d sites is shown to occur at lower temperatures than previously reported. Bulk activation energies for Li+ ion hopping range from 0.43 ± 0.03 eV powdered samples 0.53 0.01 sintered 950 °C 24 h, due loss Li during sintering elevated temperatures. A lithium coefficient 3.89 × 10-12 cm2 s-1 was...

Abstract Gallium nitride is known to have both piezoelectric and piezoresistive properties (A. D. Bykhovski et al., Appl. Phys. Lett. 68 , 818 (1996) [1] R. Gaska 71 3817(1997) [2]). GaN's inertness corrosive chemicals robustness high temperature makes it a potential candidate for harsh environment pressure sensor applications. We report gauge factor measurements done on n‐GaN. Resistor structures were fabricated 1×10 18 cm –3 n‐type doped 250 μm thick GaN subject three point bend tests. The...

Crystal structures of Li2MGe3O8 (M = Ni or Zn), in space group P4332, have been refined by application the Rietveld method to variable-temperature time-of-flight neutron powder diffraction data. Difference Fourier maps, calculated using data collected at high temperatures, showed significant negative density centered positions vacant ambient temperatures. In Li2NiGe3O8, conduction involves three-dimensional 8c–12d–8c site hopping, facilitated harmonic oscillations oxygen atoms away from...

Nowadays, there is no doubt about the high electrocatalytic efficiency that obtained when using hybrid materials between carbonaceous nanomaterials and transition metal oxides. However, method to prepare them may involve differences in observed analytical responses, making it necessary evaluate for each new material. The goal of this work was obtain first time Co2SnO4 (CSO)/RGO nanohybrids via situ ex methods their performance amperometric detection hydrogen peroxide. electroanalytical...

LiCoMnO4 with the spinel structure loses oxygen on heating in air above ∼570 °C and by ∼1050 reaches approximate stoichiometry 'LiCoMnO3' which has cation-disordered rock salt structure. On cooling, transformation is fully reversible.