共查询到20条相似文献,搜索用时 15 毫秒
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《Solid State Communications》1987,62(7):479-481
Preliminary measurement of the superconducting critical magnetic field Hc2 of LaMCuO system (M = Sr and Ba) with layered perovskite structure has been carried out. The results show a quite large anisotropy of Hc2 indicating that the present system has a two dimensional character of the electron transport. The measured conductivities seem to be consistent with the values estimated from the observed Hc2 by use of an ideal two dimensional band with free electron mass. 相似文献
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《Solid State Communications》1987,63(5):415-417
A new superconducting oxide GdxBa1−xCuO3−y with Tc (ρ=0) above 92K has been successfully synthesized by the ceramic technology. The samples with composition of x=0.5, 0.625 and 0.9 are all observed with high Tc superconductivity. The highest Tc for samples measured is observed in Gd0.5Ba0.5CuO3−y which has a resistive midpoint of 95K with a width of 1.5K, and a zero-resistance temperature of 92.5K. The results of a.c. magnetic susceptibility measurement are also reported. 相似文献
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《Solid State Communications》1987,62(4):265-269
The intermediate valent compound series Eu(Pd1−xAux)2Si2 has been studied by Mössbauer effect measurements on 151Eu(T = 4.2−300K) and 197Au (4.2K) and by X-ray diffraction (10K, 300K). The temperature induced valence transition Eu2+ → Eu3+ for x < 0.175 is not of first order type, as suggested in a previous phase diagram [1]. The valence change of the Eu-ion is reflected also in the isomer shift of the 197Au Mössbauer-resonance. 相似文献
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《Solid State Ionics》1988,31(1):41-47
Glasses were prepared in a wide range of compositions for the two systems oof mixed-cation, ZrF4BaF2LiFNaF, and mixed-anion, ZrF4BaF2LiFLiCl. Ionic conductivities were measured for these glasses and it was found that these glasses were not only cationic but also anionic conductors depending on the total alkali halide content. Four types of mixed-cation and mixed-anion effects on ionic conductivity were demonstrated for the cation-conducting and anion-conducting glasses. In cation conduction, the cation mixing caused the conductivity decline, whereas the anion mixing led to the conductivity enhancement. In anion conduction, on the other hand, the cation mixing led to the conductivity enhancement, whereas the anion mixing caused the conductivity decline. 相似文献
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《Solid State Communications》1987,64(2):217-226
Superconductivity around 90K is observed in mixed and single phase system of LnBaCuO (Ln = Y, Ho, Er). Resistivity, X-ray powder diffraction and AC susceptibility measurements were carried out on samples of the mixed phase systems Ln2−xBaxCuO4−y (Ln = Ho, Er), Y1.2Ba0.8Cu1+xO4+x−y(0<x<5) and single phase system Ba2LnCu3O7 (Ln = Y, Ho, Er). Ln2−xBaxCuO4−y consists of Ba2LnCu3O7, BaCuLn2O5, Cu2Ln2O5 and starting materials and shows a small diamagnetic signal below Tc in the temperature dependent AC susceptibility. Y1.2Ba0.8Cu1+xO4+x−y is a mixture of Ba2YCu3O7, BaCuY2O5 and CuO and also indicates a small diamagnetic signal at 92K. Interesting resistivity anomalies occur in the Y1.2Ba0.8Cu4O7−y and Ho0.8Ba1.2CuO4−y composites including large drops in the resistivity at ∼220 and ∼120K, respectively. The pure compounds, Ba2LnCu3O7 (Ln = Y, Ho, Er) show sharp resistive superconducting transitions and bulk Meissner effects of 90%. 相似文献
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B. Lamontagne F. Semond A. Adnot D. Guay D. Roy 《Applied Physics A: Materials Science & Processing》1995,61(2):187-191
In the context of the alkali-metal promotion of Si oxidation, high-pressure oxidation of potassium multilayers on cooled Si(111) has been investigated using SEM, micro-AES and AFM. The oxidation process at high pressure turns the potassium islands observed at high coverage into potassium oxides islands. A subsequent potassium desorption at moderate temperature (900 K) yields SiO2 islands (height of 20 nm and lateral dimensions of 10 m) surrounded by a thin continuous SiO2 overlayer. Other conditions such as potassium multilayer coverage exposed to a low O2 pressure, potassium monolayer or simultaneous potassium/oxygen adsorption yield a uniform SiO2 overlayer. 相似文献
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《Solid State Ionics》1987,24(4):281-287
The electromotive force (EMF) of the COCO2 sensor using Na2CO3 and NASICON (Na3Zr2Si2PO12) as solid electrolytes has been examined in COCO2Ar atmospheres. The EMF is related to the partial pressures of CO and CO2 and proportional to log(P2CO2P−1CO). The simultaneous use of the oxygen sensor of stabilized zirconia gives the EMF proportional to log(PCO2P−1CO). The EMF's of two sensors permit to determine individually partial pressures of CO and CO2. The existence of H2 with high concentration does not affect the EMF's. This fact proves the applicability of the two-sensor system to the monitoring and the controlling of reducing atmospheres in industrial processes. 相似文献
11.
The K=1/2 rotational band in
171Yb is investigated
using the particle number conserving (PNC) method for treating the cranked
shell model with monopole and quadrupole pairing interactions. The
experimental moments of inertia of
171Yb [521]1/2 (signature α =±1/2) are reproduced well by the PNC calculation, in which no free
parameter is involved. The difference in the contribution to the moment of
inertia between protons and neutrons is mainly due to the blocking effect of
neutron normal orbitals. The ω variation of the occupation
probability of each cranked orbital and the contribution to the moment of
inertia from each major shell and from each cranked orbital are
investigated. 相似文献
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《Nuclear Physics A》1988,486(2):235-252
In the framework of the microscopic IBM the fermion pair structure for several collective excitations has been investigated. In this study the deformed nucleus 156Gd is treated as an example. The theoretical method used consists of a combination of a triaxial Hartree-Fock-Bogoliubov method and a Hill-Wheeler method. We discuss the effects of keeping the structure of the collective S-, D- and G-pairs fixed as well as varying these structures. The combination of fixed S-, D-, and G-pairs with only one other set of S'-, D'- and G'-pairs is also investigated. 相似文献
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《Solid State Communications》1987,63(7):573-574
We report on measurements of the Hall-resistivity as a function of sample geometry in n-Hg0.8Cd0.2Te. The results demonstrate that the data measured with an nHgCdTe sample by Shayegan et al.1 quite recently are a mere consequence of the sample geometry and do not represent the Hall resistivity. The magneto-transport properties of pure n-HgCdTe are not identical with those of n-InSb in strong magnetic fields and at low temperatures. 相似文献
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《Physics letters. A》1998,242(6):329-336
The formation of soliton bands in the quasi-one-dimensional mixed valence planer platinum compound K2Pt(CN)4Br0.3·3.2H2O (KCP) as a result of overlapping soliton wave functions is considered. A solitonic energy band dependence on temperature and the associated phonon modes of the soliton array are suggested to be responsible for the ESR linewidth broadening observed in this material for temperatures above 85 K. 相似文献
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The superhyperfine parameters T j (j?=?x, y, z) for Cu2?+? in the square-planar K2PdX4 (X = Cl, Br) are theoretically studied from the perturbation formulas of these parameters for an octahedral 3d9 cluster, by considering both the contributions from the crystal-field and charge-transfer mechanisms. The related molecular orbital coefficients are determined from the cluster approach in a uniform way. Based on one adjustable proportional factor ρ for the orbital admixture coefficients, the calculated results of present work show reasonable agreement with the observed values. 相似文献
16.
《Physica C: Superconductivity and its Applications》2002,360(3):197-206
Superconductivity with Tc above 9 K was found in metal-deficient NbB2 prepared under 5 GPa, while no clear superconductivity was observed down to 3 K in stoichiometric NbB2. The superconductivity was observed above x=0.04 in Nb1−xB2, and the lattice parameters also changed abruptly at x=0.04. As x increased, the transition temperature Tc slightly rose and fell with the maximum value of 9.2 K at x=0.24 for the samples sintered at 5 GPa and 1200 °C. The Tc-value changed in the range from 7 to 9 K, depending on the sintering pressure. A series of Ta1−xB2 (0⩽x⩽0.24) was also synthesized under high pressure to examine a special effect of high-pressure synthesis. 相似文献
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We have theoretically and experimentally studied the quantum coherence effects of a degenerate transition Fg =3←→Fe=2 system interacting with a weak linearly polarized (with σ+ components) probe light and a strong linearly polarized (with σ+ components) coupling field. Due to the competition between the drive Rabi frequency and the Zeeman splitting, electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) are present at the different values of applied magnetic field in the case where the Zeeman splitting of excited state Δe is larger than the Zeeman splitting of ground state Δg (i.e.Δe 〉 Δg). 相似文献
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D. Gotta D. S. Covita D. F. Anagnostopoulos H. Fuhrmann H. Gorke A. Gruber A. Hirtl T. Ishiwatari P. Indelicato E. -O. Le Bigot M. Nekipelov V. Pomerantsev M. Popov J. M. F. dos Santos Ph. Schmid L. M. Simons M. Trassinelli J. F. C. A. Veloso J. Zmeskal 《Physics of Particles and Nuclei》2014,45(1):181-183
The (3p — 1s) X-ray transition to the muonic hydrogen ground state was measured with a highresolution crystal spectrometer. The assumption of a statistical population of the hyperfine levels of the muonic hydrogen ground state was directly confirmed by the experiment and measured values for the hyperfine splitting can be reported. The measurement supplements studies on line broadening effects induced by Coulomb de-excitation hindering the direct extraction of the pion-nucleon scattering lengths from pionic hydrogen and deuterium X-ray lines. 相似文献
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本文从S(u)曲线探讨T=±OK,T=±∞K四个极端状态的特性.文中讨论了在T=±OK及T=±∞K时GX=0,因此这四个极端状态均不能作为“热库”,均无热功转换的特性,不存在包含任一状态的卡诺循环.但是却存在类似于能氏定理的lim(△s)r=0及lim T=-OK T=+∞K(△s)T=0的公式.本文还对研究这些极端状态的必要性与重要性进行了探讨. 相似文献
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《Solid State Communications》1986,59(12):809-811
The isomer shift of the 6.2 keV nuclear transition of Ta181 in CuTaS3RAIN was investigated by nuclear gamma resonance spectroscopy. Relative to tantalum metal the isomer shift in CuTaS3 corresponds to +37.95±0.1 mm/s. The z component of the electric field gradient at the nuclear site of Ta181 was found to be Vzz = (−1.29±0.01)·1018 v/cm2. The close correlation between the isomer shift in CuTaS3 and the electronegativity of the Ta-ligands is pointed out. 相似文献