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1.
Indium oxide nanobelts of growth directions of [100] type (majority) and [120] type (minor) have been found. The two types of nanobelts have the top and bottom surfaces being (001), while the [100] type nanobelts have side surfaces of (010) and a rectangular cross-section, and the [120] type nanobelts have a parallelogram cross-section. The nanobelts have a perfect crystal structure without the presence of line or planar defects. 相似文献
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V. F. Masterov A. V. Prikhod’ko O. I. Kon’kov A. A. Shaklanov 《Physics of the Solid State》1997,39(1):84-86
Electrical properties of Cu-O monolayers intercalated into crystalline graphite have been studied at microwave frequencies
(up to 1 GHz) in the temperature range 80–400 K. As the temperature increases above 300 K, the resistance of the starting
graphite samples increases because of oxygen desorption. Heating a sample containing intercalated Cu-O layers results in a
transition from the metallic to the semiconducting (or insulating) state in the 95–130 K interval. At T=8 K, the samples exhibit microwave absorption typical of superconductors (this effect is not observed at T=260 K).
Fiz. Tverd. Tela (St. Petersburg) 39, 97–100 (January 1997) 相似文献
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Three zwitterionic surfactants, dodecyl dimethyl carboxylbetaine (DCB), dodecyl dimethyl sulfobetaine (DSB) and N-dodecyl-β-aminoprpionate (DAP), intercalated into NiZn-layered hydroxide salts (NZL-DCB, NZL-DSB and NZL-DAP) were synthesized by the coprecipitation method. The effect of surfactant content, pH, temperature and time of hydrothermal treatment on preparation was investigated and discussed. The NZL-DCB, NZL-DSB and NZL-DAP were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry analysis and differential thermal analysis (TGA/DTA). The results showed that basal spacings of NZL-DCB, NZL-DSB and NZL-DAP were around 3.45, 3.68 and 3.94 nm, respectively. DCB, DSB and DAP probably form an overlapped bilayer in the gallery. TGA/DTA data indicated that NZL-DCB, NZL-DSB and NZL-DAP displayed three loss weight stages: loss of adsorbed and structural water, dehydroxylation of matrix and decomposition of nitrate ions, decomposition and combustion of surfactants. Furthermore, chemical analysis data, BET surface area and scanning electron microscopic (SEM) were also measured and analyzed. 相似文献
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《Comptes Rendus Physique》2002,3(2):153-161
In granular media, dissipation leads to interesting phenomena like cluster formation in non-equilibrium dynamical states. As an example, the freely cooling system is examined concerning the energy decay and the cluster evolution with time. Furthermore, the probability distribution of the collision frequency is discussed. Uncorrelated events lead to a Poisson distribution for the collision frequencies in the homogeneous system, whereas cooperative phenomena can be related to a power-law decay of the collision probability per unit time. To cite this article: S. Luding, C. R. Physique 3 (2002) 153–161. 相似文献
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W. Reichardt F. Gompf M. Aïn B. M. Wanklyn 《Zeitschrift für Physik B Condensed Matter》1990,81(1):19-24
By inelastic neutron scattering we have measured phonon dispersion curves of CuO in several directions. The phonon data are well reproduced by a 22 parameter rigid ion model. Various models with reduced numbers of fit parameters are described. 相似文献
7.
Li2O finds several important technological applications, as it is used in solid-state batteries, can be used as a blanket breeding
material in nuclear fusion reactors, etc. Li2O exhibits a fast ion phase, characterized by a thermally induced dynamic disorder in the anionic sub-lattice of Li+, at elevated temperatures around 1200 K. We have carried out lattice-dynamical calculations of Li2O using a shell model in the quasi-harmonic approximation. The calculated phonon frequencies are in excellent agreement with
the reported inelastic neutron scattering data. Thermal expansion, specific heat, elastic constants and equation of state
have also been calculated which are in good agreement with the available experimental data. 相似文献
8.
S.K. Agarwal 《Solid State Communications》1981,39(3):513-516
Phonon dispersion curves, for MgO, have been calculated, for the first time, in the framework of the modified three body force shell model (TSM), assuming both the positive and negative ions to be polarizable. The results are in good agreement with the inelastic neutron scattering measurements and are somewhat better than our earlier one-ion polarizable TSM calculations. It has been possible to conclude that a revised set of values of the elastic constants which are relatively larger, is essentially responsible to lead to a better set of model parameters and hence of the phonon frequencies. 相似文献
9.
《Solid State Ionics》2006,177(19-25):1635-1637
This work shows how the combination of quasi-equilibrium (chronopotentiometry) and kinetical measurements (electrochemical impedance) is able to extract ionic mobility values like the jump diffusion coefficient DJ. Results are presented on the jump diffusion coefficient variation with composition of several cations (Li+, Na+, and K+) intercalated into electron beam evaporation-prepared a-WO3 thin films. DJ exhibits higher values for the smallest ion (Li+), and decreases as the ion size enlarges. In all cases DJ shows lower values for high intercalation levels. It is noted that the type of cation rather influences transport mechanisms than equilibrium properties (insertion thermodynamics). The energy barrier of ion hopping is analyzed in light of available microscopic diffusion models and theoretical simulations. 相似文献
10.
Mitiko Miura Hitoshi Arimori Hiromu Murata Akiko Kida Kazuaki Iishi 《Journal of Physics and Chemistry of Solids》1983,44(7):627-631
The effect of the electronic extension on the electrostatic potential was first taken into account functionally by Birman. We have applied his model to the lattice dynamics of CaO, where the degree of the electronic extension w was defined and determined with the use of the electronic charge density distribution obtained from analysis of X-ray data. Our treatment shown here not only gives a physically meaningful model including the feature of the electronic extension, but also involves essentially the same very simple process as the conventional point-charge model but with fewer adjustable parameters. Good reproduction of calculated phonon dispersion curves was obtained by taking into account the electronic extension, although the degree of the electronic extension, w, used to fit the curve was a little larger than that derived from the observed data owing to the first rough approximation for the potential energy arising from the electronic extension. 相似文献
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M. Jouanne T. Sekine C. Julien 《Applied Physics A: Materials Science & Processing》1990,51(4):347-349
Co-insertion of solvent into layered compounds intercalated with lithium has been evidenced by Raman scattering measurements. The penetration of solvated species into the host is observed in samples prepared by an electrochemical technique as well as by direct chemical reaction in n-butyl lithium. The co-insertion is evidenced by the appearance of peaks in the spectral range 1200–1800 cm–1 which are attributed to vibrations due to carbon atoms. 相似文献
12.
Peculiar diffusion behavior of AlCl_4 intercalated in graphite from nanosecond-long molecular dynamics simulations
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《中国物理 B》2021,30(10):107102-107102
The diffusion property of the intercalated species in the graphite materials is at the heart of the rate performance of graphite-based metal-ion secondary battery. Here we study the diffusion process of a AlCl_4 molecule within graphite — a key component of a recently reported aluminum ion battery with excellent performance — via molecular dynamics(MD) simulations. Both ab-initio MD(AIMD) and semiempirical tight-binding MD simulations show that the diffusion process of the intercalated AlCl_4 molecule becomes rather inhomogeneous, when the simulation time exceeds approximately 100 picoseconds. Specifically, during its migration in between graphene layers, the intercalated AlCl_4 molecule may become stagnant occasionally, and then recovers its normal(fast) diffusion behavior after halting for a while. When this phenomenon occurs, the linear relationship of the mean squared displacement(MSD) versus the duration time is not fulfilled. We interpret this peculiar behavior as a manifestation of inadequate sampling of rare event(the stagnation of the molecule), which does not yet appear in short-time MD simulations. We further check the influence of strains present in graphite intercalated compounds(GIC) on the diffusion properties of AlCl_4, and find that their presence in general slows down the diffusion of the intercalated molecule, and is detrimental to the rate performance of the GIC-based battery. 相似文献
13.
Classical molecular dynamics was used to investigate the equilibrium state of the surface region of as-grown La2O3. It is currently thought that bulk and epitaxial thin film La2O3 surfaces exhibit amorphous structures in the as-prepared state that yield bulk crystal states upon postdeposition annealing. The focus of the study is to determine if the as-prepared surface region of La2O3 is purely amorphous as indicated from prior experimental results. Using simulation cells sufficiently large to accommodate the formation of defects, phase segregation, compositional migration, and site defects, our results show that crystalline phases are evident from simulated X-ray diffraction patterns. Although the phase of these crystallites is unresolved, we suggest that combinations of distorted hexagonal, cubic, and nonstoichiometric phases are formed in the as-prepared state prior to annealing. These crystallites likely serve as nucleation site for long-range ordered crystal growth upon annealing. 相似文献
14.
This paper presents a mechanism of decay of elementary particles, which has been developed based on a new approach. The results obtained may be of interest to experimenters engaged in the decay of Z
0 bosons. Schemes and modes of the structural decay of gamma structures, one of which is the Z
0 boson, are given. Analysis of the schemes and modes of the structural decay has shown that the decays of the product triple-quark particles (products of the decay of a Z
0 boson into triple-quark particles) result in the occurrence of a new mode of decay – the decay of one triple-quark particle into three triple-quark particles. According to the proposed mechanism of the decay of particles, an electron, a muon, a triton, and a gamma photon are particles consisting of a quark–antiquark pair and having a spin equal to unity. 相似文献
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The water-surface interaction is a research target of great importance for a broad spectrum of technological applications and fundamental scientific disciplines. In the present study, a comparative analysis is performed to clarify the structural and diffusion properties of water on a number of oxide surfaces. Based on the molecular dynamics (MD) simulation method, the water-surface interaction mechanism was investigated for the oxide materials TiO2 (anatase), Al2O3 (corundum), and Fe2O3 (hematite). A comparison of the water-TiO2 interaction with the water-Al2O3 and water-Fe2O3 systems demonstrates the specificity of the adsorption and layer formation on the atomic/molecular level scale. The obtained MD analysis data point to a considerable enhancement of water-TiO2 surface adsorption and a relatively high density distribution profile near the surface. The novel data on water structure and diffusion on oxide surfaces are discussed from the point of view of possible material innovation and design. 相似文献
18.
Leidlmair C Wang Y Bartl P Schöbel H Denifl S Probst M Alcamí M Martín F Zettergren H Hansen K Echt O Scheier P 《Physical review letters》2012,108(7):076101
Helium adsorbed on C(60)(+) and C(70)(+) exhibits phenomena akin to helium on graphite. Mass spectra suggest that commensurate layers form when all carbon hexagons and pentagons are occupied by one He each, but that the solvation shell does not close until 60 He atoms are adsorbed on C(60)(+), or 62 on C(70)(+). Molecular dynamics simulations of C(60)He(n)(+) at 4 K show that the commensurate phase is solid. Helium added to C(60)He(32)(+) will displace some atoms from pentagonal sites, leading to coexistence of a registered layer of immobile atoms interlaced with a nonregistered layer of mobile atoms. 相似文献
19.
小碳团簇结构的从头算分子动力学模拟 总被引:5,自引:0,他引:5
引入第一原理密度泛函理论, 即赝势密度泛函在实空间的有限差分方法和朗之万分子动力学退火技术, 对碳团簇Cn(n=2-8)的基态结构进行了理论计算, 所得结果与其他作者的计算结果及实验数据吻合较好. 相似文献