Abstract Enzymes are extremely complex catalytic structures with immense biological and technological importance. Nevertheless, their widespread environmental implementation faces several challenges, including high production costs, low operational stability, intricate recovery reusability. Therefore, the de novo design of minimalistic biomolecular nanomaterials that can efficiently mimic biocatalytic function (bionanozymes) overcome limitations natural enzymes is a critical goal in...

We report the observation of magnetoelectric and magnetodielectric effects at different temperatures in Mn-substituted yttrium orthoferrite, ${\mathrm{YFe}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}{\mathrm{O}}_{3}(0.1\ensuremath{\le}x\ensuremath{\le}0.40)$. Substitution Mn antiferromagnetic ${\mathrm{YFeO}}_{3}({T}_{N}=640\text{ }\text{ }\mathrm{K})$ induces a first-order spin-reorientation transition temperature, ${T}_{\mathrm{SR}}$, which increases with $x$ whereas N\'eel temperature...

Raman study on a select few orthochromites, RCrO 3 (R = Y, Lu, Gd, Eu and Sm) shows that the phonon behavior at T N in compounds with magnetic R-ion (Gd is remarkably different from of non-magnetic (Y, Lu Eu).While anomalies most observed frequencies all these may result distortion CrO 6 octahedra due to size effect magnetostriction arising Cr-ordering, anomalous their linewidths for only suggests spin-phonon coupling.The presence coupling low frequency modes related motion orthochromites Gd...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTHigh-Pressure Synthesis and Characterization of Incompressible Titanium PernitrideVenkata S. Bhadram*, Duck Young Kim, Timothy A. Strobel*View Author Information Geophysical Laboratory, Carnegie Institution Washington, DC 20015, United States*(T.A.S.) E-mail: [email protected]*(V.S.B.) protected]Cite this: Chem. Mater. 2016, 28, 6, 1616–1620Publication Date (Web):March 7, 2016Publication History Received5 January 2016Revised29 February...

Interpenetrating metal organic frameworks are interesting functional materials exhibiting exceptional framework properties. Uptake or exclusion of guest molecules can induce sliding in the making it porous non‐porous. To understand this dynamic nature and how interaction changes during sliding, (MOF) 508 {Zn(BDC)( 4,4′‐Bipy) 0.5 · DMF(H 2 O) } was selected for study. We have investigated structural transformation MOF‐508 under variable conditions temperature, pressure gas loading using Raman...

Two distinct ferromagnetic phases of LaMn(0.5)Co(0.5)O(3) having monoclinic structure with physical properties have been studied. The ordering temperature T(c) is found to be different for both the phases. origin such contrasting characteristics assigned changes in distance(s) and angle(s) between Mn-O-Co resulting from distortions observed neutron diffraction studies. Investigations on dependent Raman spectroscopy provide evidence structural characteristics, which affects exchange...

We report a comparative study of the performance infrared (IR) photoconductive and bolometric detectors fabricated from few layer graphene (FLG) to graphitic films obtained by different methods. FLG grown directly on insulating substrates with aid residual hydrocarbons polymethylmethacrylate (PMMA) carbon sources show an IR photoresponse 73% which is far higher compared (6-14%) CVD Scotch tape The nature due generation photoexcited charge carriers. On other hand, bulk in where resistance...

Metastable nitrogen-rich phases are of technological interest as they may possess a range useful electronic, optical and mechanical properties. Cubic-Ti${}_{3}$N${}_{4}$ is long-sought-after metastable phase analogous to other ${M}_{3}$N${}_{4}$ (M = tetravalent metal) compounds that were discovered in the past decade. By marrying first-principles calculations with laser-heated diamond anvil cell experiments, authors present first experimental discovery characterization...

The motivation of the present work is to understand optical, chemical, and electrical aspects proton transfer mechanism indole (I) some carbonyl based derivatives: indole-3-carboxaldehyde (I3C) indole-7-carboxaldehyde (I7C) for both powder form their liquid solution. Structural information derivatives (isolated molecule in solution) obtained with density functional theory (DFT) time dependent DFT (TD-DFT) methods. Calculated transition energies are used generate UV-vis, FTIR, Raman, NMR...

In this article, we report non-Arrhenius behavior in the temperature-dependent dc conductivity of alkali ion conducting silicate glasses well below their glass transition temperature. contrast to several fast ion-conducting and binary potassium glasses, these show a positive deviation Arrhenius plot. The observed is completely reproducible nature even after prolonged annealing close temperature respective sample. These results are manifestation local structural changes network with give rise...

Temperature-dependent Raman spectroscopy and X-ray diffraction studies have been carried out on NH4HSO4 single crystals in the temperature range 77–298 K. Two structural transitions driven by molecular ordering change crystal symmetries are observed below 263 143 These phase marked anomalies dependence of wavenumber fwhm several internal vibrational modes. The spectra data enable us to understand nature resulting ferroelectric K, sandwiched between two nonferroelectric phases. structure is...

The effect of rare-earth ion size on the octahedral distortions in chromites (RCrO 3 , R = Lu, Tb, Gd, Eu, Sm) crystallizing orthorhombic structure has been studied using Raman scattering and synchrotron powder x-ray diffraction up to 20 GPa.From our studies RCrO we found that tilts (distortions) increase with pressure.This is contrary earlier report which suggests LaCrO decrease pressure leading a more ordered phase at high pressure.Here observe rate distortion decreases R-ion radii.This...

The pressure-dependent phase behavior of semiconducting chalcopyrite ZnSiP2 was studied up to 30 GPa using in situ X-ray diffraction and Raman spectroscopy a diamond-anvil cell. A structural transition the rock salt type structure observed between 27 GPa, which is accompanied by soft phonon mode simultaneous loss signal optical transmission through sample. high-pressure possesses cationic disorder as evident from broad features patterns. low-frequency modes during compression establishes...

Noting that BiI3 and the well-known topological insulator (TI) Bi2Se3 have same high symmetry parent structures, it is desirable to find a wide-band gap TI, we determine here effects of pressure on structure, phonons electronic properties rhombohedral BiI3. We report pressure-induced insulator-metal transition near 1.5 GPa, using electrical resistivity Raman measurements. X-ray diffraction studies, as function pressure, reveal structural peculiarity crystal, with drastic drop in c/a ratio at...

We describe a transfer-free method for the fabrication of nanocrystalline graphene (nc-graphene) on SiO2 substrates directly from patterned carbonaceous deposits. The deposits were produced residual hydrocarbons present in vacuum chamber without any external source by using an electron beam induced deposition (EBICD) process. Thermal treatment under conditions presence Ni catalyst transformed EBIC deposit into nc-graphene patterns, confirmed Raman and TEM analysis. patterns have been...

Temperature dependent Brillouin scattering studies have been performed to ascertain the influence of solvent dynamics on ion-transport in succinonitrile-lithium salt plastic crystalline electrolytes. Though very rarely employed, we observe that spectroscopy is an invaluable tool for investigation dynamics. Analysis various acoustic (long wavelength) phonon modes observed spectra reveal trans-gauche isomerism and as well ion-association effects ion transport. Although pristine SN dilute...

Theoretical predictions of ZnO:MnO solid solutions (abbreviated here as ZMO) with the rocksalt-type structure suggest improved visible light absorption and suitable band edge positions for overall water splitting reaction, but experimental efforts to produce such phases are limited by low solubility Zn within this type. Here, we ZnxMn1–xO, x = 0.5 0.3 in metastable rocksalt phase, using high-pressure high-temperature (HPHT) techniques. X-ray diffraction electron microscopy methods were...

Temperature-dependent Raman spectroscopic studies have been carried out on KHSO4 single crystals in the temperature range 298−493 K. A structural phase transition driven by lattice and molecular disorder is observed at 473 The spectral data enable an understanding of nature across leading to superionic phase. HSO4− polymeric hydrogen-bonded chain a higher symmetry high clearly captured from our results. internal S−OH S−O stretching modes and, limited extent, external throw light mechanism...

Electron beam-induced carbonaceous deposition (EBICD) derived from residual hydrocarbons in the vacuum chamber has many fascinating properties. It is known to be chemically complex but robust, structurally amorphous, and electrically insulating. The present study an attempt gain more insight into its chemical electrical nature based on detailed measurements such as Raman, XPS, TEM, electrical. Interestingly, EBIC patterns are found blue fluorescent when excited with UV radiation, a property...

The rotational and translational dynamics of molecular hydrogen trapped within β-hydroquinone clathrate (H_{2}@β-HQ)-a practical example a quantum particle an anisotropic confining potential-were investigated using inelastic neutron scattering Raman spectroscopy. High-resolution vibrational spectra, including those collected from the VISION spectrometer at Oak Ridge National Laboratory, indicate relatively strong attractive interaction between guest host with strikingly large splitting...

Single crystals of LaMn0.5Co0.5O3 belonging to the ferromagnetic-insulator and distorted perovskite class were grown using a four-mirror optical float zone furnace. The as-grown crystal crystallizes into an orthorhombic Pbnm structure. spatially resolved 2D Raman scan reveals strain-induced distribution transition metal (TM)–oxygen (O) octahedral deformation in crystal. A rigorous annealing process releases strain, thereby generating homogeneous distortion. octahedra tilt by reducing bond...

By means of in situ synchrotron X-ray diffraction and Raman spectroscopy under hydrostatic pressure, we investigate the structural stability quadruple perovskite LaMn7O12. At 34 GPa, data unveil a first-order phase transition from monoclinic I2/m to cubic Im-3 symmetry characterized by pronounced contraction unit cell significant modifications phonon modes. The is also marked suppression Jahn-Teller distortion which present ambient phase. In addition, above 20 GPa sudden simultaneous...

Previous high-pressure dielectric and diffraction studies on rubidium hydrogen sulfate (RbHSO4) observed ferroelectric phase transition below 1 GPa pressure. We have performed Raman spectroscopy RbHSO4 up to a maximum pressure of 5.15 at ambient temperature understand the microscopic origin mechanism transition. On basis dependence mode frequencies their full-width half-maxima, we around 0.3 GPa, similar discovered in measurements, followed by another 2.4 GPa. These transitions are evident...