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21.
Effects of Interfacial Polarization on Voltage Tunability of Pb(Fe1/2Nb1/2)1-xTixO3 Single Crystals
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The voltage tunability of Pb(Fe1/2Nb1/2)1-xTixO3 single crystals is investigated at a low electric field (<130 V/cm) in a low frequency range (<1 MHz). The results show that the capacitance is strongly suppressed by the applied dc biases for both the rhombohedral sample and the tetragonal sample. A negative voltage tunability is only detected in the tetragonal sample. The origin of the giant tunability and the negative tunability is discussed based on the multipolarization-mechanism model and the equivalent circuit model, respectively. It is ascribed to the interfacial polarization at the interface of electrode/sample. 相似文献
22.
B.K. Bammannavar 《Journal of magnetism and magnetic materials》2009,321(5):382-387
Magneto electric composites with composition (x) Ni0.5Zn0.5Fe2O4+(1-x) Ba0.8Pb0.2Zr0.8Ti0.2O3 (BPZT—barium lead zirconate titanate) in which x varies as 0.0, 0.15, 0.30, 0.45 and 1.0 mol% were prepared by standard double sintering ceramic method. The presence of constituent phases such as ferrite and ferroelectric was confirmed by X-ray diffraction. The structural analyses were carried out by using X-ray diffraction pattern. Scanning electron micrographs (SEM) were taken to understand the microstructure of the samples. The calculated values of the porosity of the samples lie between 4.5% and 16.2%. The hysteresis measurements were made to determine saturation magnetization (Ms), magnetic moment (μB) and coercivity (Hc). From the AC susceptibility measurements the contribution of both the single domain (SD) particles of the ferrite phase and mixed domain (SD+MD) particles of the composites in ME output were explained. The static magneto electric voltage coefficients (dE/dH)H were measured as a function of intensity of magnetic field and the maximum ME coefficient were observed for the composites with 30% of ferrite+70% of ferroelectric phase. 相似文献
23.
We approach the thermodynamic properties of the d-dimensional RN black holes, discuss the three expressions for the first law of thermodynamics for black holes and calculate the energies in the three regions of the black hole spacetimes. Some remarks of the first law of thermodynamics and the thermal properties for the black holes are given. 相似文献
24.
《Physics and Chemistry of Liquids》2012,50(3):229-236
Assuming the quasi-crystalline model for the multi-component liquid systems, the effective Debye temperature has been investigated from the density and sound velocity measurements of three ternary and three quaternary liquid systems containing n-alkanes over the entire range of mole fractions at 298.15?K. The results obtained have been interpreted in terms of intermolecular interactions and modifications of the internal structure of the mixtures. 相似文献
25.
H. Haberland B. v. Issendorff R. Fröchtenicht 《Zeitschrift für Physik B Condensed Matter》1995,98(3):417-419
Ionized argon clusters were generated by electron impact ionization of neutral argon clusters embedded in large neutral helium clusters. Photofragmentation spectroscopy of Ar
3
+
and Ar
3
+
He produced in this way demonstrates the strong influence of vibrational excitation on the photodissociation dynamics, and indicates the low internal energy of the latter cluster. 相似文献
26.
F. Ancilotto E. Cheng M. W. Cole F. Toigo 《Zeitschrift für Physik B Condensed Matter》1995,98(3):323-329
Alkali atoms have been shown previously to have only unstable binding states inside liquid4He. We calculate the equilibrium configurations and binding energies of single alkali atoms near the liquid-vapor interface of4He and3He. A simple interface model is used to predict the surface deformation due to the presence of the atoms. A more realistic density functional model yields somewhat higher energies in the case of4He. For all alkali atoms, we find the surface binding energies to be around 10 to 20 K. A similar analysis with atom-H2 interactions finds that alkali atoms tend to submerge into liquid H2, with the exception of Li. 相似文献
27.
K. Fuke K. Tsukamoto F. Misaizu 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(Z1):204-206
Photoionization thresholds of Si
n
(n=2–40) were examined by vacuum UV radiation (5.7–8.5 eV) generated by stimulated Raman scattering of narrow-bandwidth 193-nm radiation in high pressure hydrogen and deuterium gases. A strong threshold energy dependence on cluster size is observed, featuring major maxima at 10 and 20. The magic behavior atn=10 is consistent with the results of the photofragmentation and CID experiments reported previously. 相似文献
28.
The CdSe nanocrystals with different sizes were synthesized in aqueous solution through water-sol method using l-cysteine hydrochloride as the stabilizer. The pH-dependent optical properties of the CdSe nanocrystals were investigated. Furthermore, the CdSe nanocrystals were dispersed into chloroform by using a cationic surfactant, and mixed with poly(N-vinylcarbazole) (PVK) in different mass ratios. The investigation of the photoluminescence (PL) and absorption spectra of the CdSe:PVK blends suggested that energy transfer from the PVK excited states to the CdSe nanocrystals, and it is more efficient for the smaller size nanocrystals. In the meantime, it was found that the relative emission intensity of the CdSe nanocrystals to PVK in the blends depended on the mass ratios, and the emission from the CdSe nanocrystals was the strongest as the mass ratio of CdSe to PVK was 2:1. 相似文献
29.
30.
Miniaturized magnetic guide for neutral atoms 总被引:1,自引:0,他引:1
J. Fortagh H. Ott A. Grossmann C. Zimmermann 《Applied physics. B, Lasers and optics》2000,70(5):701-708
We describe the principle and realization of a miniaturized magnetic guide for neutral atoms. The magnetic guide in our experiment
is formed by a micrometer-sized current-carrying wire which is attached to a second, thick wire. The conductors are electrically
insulated from each other. The combined magnetic field of both conductors provides an approximately linear trapping potential
which establishes a magnetic guide along the surface of the thin wire. The miniaturized waveguide is filled with rubidium
atoms from a magneto-optical trap (MOT) by first loading the atoms into a spherical magnetic quadrupole trap which is subsequently
transformed into the linear potential of the waveguide. As thermal source for Rb atoms we use an alkali metal dispenser which
is located close to the center of the MOT. This novel method is compatible with ultrahigh vacuum conditions and we achieved
lifetimes of the magnetically trapped atoms up to 100 s.
Received: 18 October 1999 / Published online: 24 March 2000 相似文献