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141.
Ferromagnetic rare-earth-based inverse perovskites Gd3AlX (X = B, N) are studied using hybrid functionals in the framework of density functional theory. Different exchange correlation potentials are employed to analyze the structural parameters and geometry of the materials. The spin polarization and band structure explain the metallic behavior of these materials with high values of magnetic moment. The calculated elastic constants specify all materials are ordered perovskite compounds, among which Gd3GaB, Gd3GaN, Gd3InN are brittle in nature while as Gd3InB is ductile in nature. The quasi-harmonic Debye model was used to predict the thermodynamic properties of the material. The analysis of thermoelectric properties viz. Seebeck coefficient, electronic and thermal conductivities at higher temperature has been carried out. To check the optoelectronic response of the material various optical properties have been calculated up to 14 eV photon energy range. The competent thermoelectric and optoelectronic properties with high value of magnetic moment and ductile character suggests the application in thermoelectric and electro-optic devices. 相似文献
142.
Mehroz Iqbal Jameela Fatheema Qandeel Noor Malika Rani Muhammad Mumtaz Ren-Kui Zheng Saleem Ayaz Khan Syed Rizwan 《Materials Today Chemistry》2020
This study reports first synthesis of MXene-derived co-existing magnetic phases. New family of two-dimensional (2D) materials such as Ti3C2 namely MXene, having transition metal forming hexagonal structure with carbon atoms have attracted tremendous interest now a days. We have reported structural, optical and magnetic properties of un-doped and La-doped Ti3C2Tx MXene, synthesized using co-precipitation method. The lattice parameter (LP) calculated for La-MXene are a = 5.36 Å, c = 18.3 Å which are slightly different from the parent un-doped MXene (a = 5.35 Å, c = 19.2 Å), calculated from X-ray diffraction data. The doping of La+3 ions shrinks Ti3C2Tx layers perpendicular to the planes. The band gap for MXene is calculated to be 1.06 eV which is increased to 1.44 eV after doping of La+3 ion that shows its good semiconducting nature. The experimental results and density functional theory (DFT) calculations for magnetic properties of both the samples have been presented and discussed, indicating the co-existence of ferromagnetic-antiferromagnetic phases. The results presented here are novel and is first report on co-existence of magnetic properties of 2D carbides for potential applications in two-dimensional spintronics. 相似文献
143.
Mike JF Nalwa K Makowski AJ Putnam D Tomlinson AL Chaudhary S Jeffries-El M 《Physical chemistry chemical physics : PCCP》2011,13(4):1338-1344
Herein we report the synthesis of two solution processible, conjugated polymers containing the benzobisoxazole moiety. The polymers were characterized using (1)H NMR, UV-Vis and fluorescence spectroscopy. Thermal gravimetric analysis shows that the polymers do not exhibit significant weight loss until approximately 300 °C under nitrogen. Cyclic voltammetry shows that the polymers have reversible reduction waves with estimated LUMO levels at -3.02 and -3.10 eV relative to vacuum and optical bandgaps of 2.04-2.17 eV. Devices based on blends of the copolymers and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) exhibited modest power conversion efficiencies. Theoretical models reveal that there is poor electron delocalization along the polymer backbone, leading to poor performance. However, the energy levels of these polymers indicate that the incorporation of benzobisoxazoles into the polymer backbone is a promising strategy for the synthesis of new materials. 相似文献
144.
Alves G Morel L El-Ghozzi M Avignant D Legeret B Nauton L Cisnetti F Gautier A 《Chemical communications (Cambridge, England)》2011,47(27):7830-7832
A platinum Chugaev complex was synthesised and fully characterized by multinuclear NMR spectroscopy and X-ray crystallography. This cis bis acyclic diamino carbene complex acts as a cytotoxic compound and behaves as a cisplatin equivalent by interacting with supercoiled DNA and thiols. Stability of the ligand is also discussed. 相似文献
145.
Sabri Messaoudi Bechir Bejaoui Fourat Akrout Malika Bel Hassen Cherif Sammari 《International journal of quantum chemistry》2013,113(11):1633-1640
The heterogeneous uptake of N2O5 on mineral dust particles may play an important role in the removal of nitrogen oxides from the atmosphere. However, the reaction of N2O5 with the mineral particles is not well understood. The reaction of N2O5 with two Si(OH)4 monomers is explored using theoretical methods. This study represents a first step towards understanding the interaction of N2O5 with the hydroxyl groups of silica particles. Energies are calculated using MP2 single point calculations on the B3LYP optimized geometries and including B3LYP thermodynamic corrections. Four mechanisms are considered for the formation of two HNO3 and one H6Si2O7. The rate limiting activation barrier of the most favorable path is found to be 12.5 kcal mol?1. This reaction appears to be more favorable than the hydrolysis of N2O5 with one water molecule. These results are in agreement with experimental observations, which show that N2O5 reacts with OH groups of Saharan dust to form nitrate. © 2012 Wiley Periodicals, Inc. 相似文献
146.
In this study, we synthesized hybrid materials using well-Dawson polyoxometalates (POMs), K7[H4PW18O62]·18H2O or K6[P2W18O62]·13H2O and a room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). K, W, P and CHN elemental analysis showed that one mole of [H4PW18O62]7− reacts with 6 moles of BMIM+ and one mole of [P2W18O62]6− reacts with 4 moles of BMIM+ to form, respectively, K[BMIM]6H4PW18O62 and K2[BMIM]4P2W18O62. X-ray diffraction illustrated amorphous structure of the hybrid materials. FT-IR spectra showed the presence of both 1-butyl-3-methylimidazolium cation and the Dawson anion. TG analysis displayed a relative thermal stability of the hybrid materials compared to the parents Dawson POMs. Cyclic voltammetry showed that the reduction peak potentials of the Dawson anion in the hybrid materials shift towards negative values and the shift is more pronounced for K[BMIM]6H4PW18O62 compared to K2[BMIM]4P2W18O62. This was attributed to a decrease in the acidity of the Dawson POM anion in the hybrid material. 相似文献
147.