共查询到20条相似文献,搜索用时 343 毫秒
1.
The specific heat (Cp) of the amorphous alloys Ni100-xZrx for x = 75, 65, 55 and 35 was measured from 0.8K to 40K and the composition trends of the transition temperature Tc, the enhanced density of states at the Fermi level Nγ(F) and the Debye temperatures θD(0), θD(T) established. For the three superconducting compositions (x=75, 65, 55) Nγ(EF increases rapidly with increasing [Zr] in agreement with the trend in amorphous Cu-Zr alloys. However, for the Zr-Ni alloys the bare density of states increases strongly with [Zr] in contrast to the Zr-Cu alloys where it is reported to be almost constant. We conclude that for the Ni-Zr alloys the electron-ion matrix element <I2> decreases with increasing [Zr]. Other results are related to recent photoemission studies of these alloys. 相似文献
2.
R. Oppermann 《Solid State Communications》1982,44(8):1297-1299
An n-orbital model describing both elastic impurity scattering and exchange interaction is examined near its instability for itinerant ferromagnetism. At the critical point and at zero temperature, long range spin fluctuations cause anomalous enhancements of the density of states near the Fermi energy with in three-dimensions (3D) and with ln2|E ? EF| in 2D. An estimation of the conductivity in a continuum analog model reveals Ω -and ln2-corrections in 3D and 2D respectively. 相似文献
3.
XPS core level binding energy shifts of the energy levels of Pd and Ag for a large number of coevaporated PdxAg1-x alloys with 0?x?1 have been measured. An analysis of the Pd level shifts yields the heats of formation of the PdAg alloy system in good agreement with those reported from calorimetric measurements. Combining these data with the Ag level shifts one obtains the heat of formation of Cd diluted into PdxAg1-x. 相似文献
4.
Assuming that the sea quark distribution vanishes for x > 0.3, we analyse the F2Fe(x, Q2) and F2D(x, Q2) structure functions measured by the European Muon Collaboration in the framework of a thermodynamical model of the valence quarks. The experimental ratio is well reproduced over the whole x range by the ratio of two valence quark distributions at different temperatures T and confinement volumes V. We obtain TD?TFe≈3 MeV and . 相似文献
5.
We have calculated the magnetic susceptibility of a praseodymium Kondo system in the Anderson model.This calculation explains correctly the negative conduction electron polarization found in the Kondo system La1?xPrxSn3 and gives an evaluation of the parameter in satisfactory agreement with other determinations. 相似文献
6.
The temperature coefficient of the CdxHg1?xTe energy gap dEg/dT as a sum of lattice dilatation and the phonon-electron interaction terms has been calculated as the function of molar composition x, for 0?x?0.3, in the temperature range 4.2–300 K. A non-linear dependence of vs x and a strong effect of temperature on values have been obtained and a comparison with experimental data is discussed. 相似文献
7.
8.
Ternary Ni50Mn50-xSnx alloys have been studied by means of the magnetothermal analysis. The high temperature phase of the Ni2MnSn Heusler alloy is obtained directly from the melt (structure of B2 type). From the paramagnetic behaviour of the Heusler alloy in the liquid as well as solid states, the same magneton number per Mn atom results. At lower temperatures this phase forms the L21 structure and shows a resulting ferromagnetic magneton number , a value which is well known. 相似文献
9.
Calculations of vibrational and rotational level spacings of homonuclear inert gas diatomic molecules by numerical integration of the radial Schrödinger equation are presented. The potentials which were used for the ground states of Ar2, Kr2, and Xe2 were obtained from accurate fits to the molecular beam scattering data. From the calculated and Bv's, the following spectroscopic constants (in cm?1) were fitted: for Ar2ωe = 31.92, ωexe = 3.31, ωeye = 0.11, Be = 0.060, αe = 0.004; for , , , , ; for , , , , . 相似文献
10.
H. Sakai R.K. Bhowmik S. Brandenburg J.H. Van Dijk A.G. Drentje M.N. Harakeh Y. Iwasaki R.H. Siemssen S.Y. Van Der Werf A. Van Der Woude 《Nuclear Physics A》1985,441(4):640-675
The γ-decay of deep-hole states in 101, 105, 107Pd was studied via the (3He, αγ) reaction at E3he = 70 MeV and supplemented by data from 112, 118Sn targets to investigate the deep-hole spreading mechanism. The γ-decay pattern for the deep-hole state shows a strong dependence on the spreading width: if the deep-hole state is observed as a sharp peak, it mainly decays to the low-lying state by a spin-flip M1 transition with a large M1-E2 mixing ratio; if the deep-hole state is observed as a broad bump, it decays statistically indicating the complete spreading of the hole strength over the underlying states; if the deep-hole state is observed with a structure intermediate between a sharp peak and broad bump, its γ-decay shows both decay patterns.A sharp peak at Ex = 2.396 MeV in 101Pd which carries a large fraction of the hole strength (C2S = 2.0) was found to be a single state having a width of less than 2.5 keV.For the spin-flip M1 transition the destructive interference between the component and the coupled components of the deep-hole state was found in heavily spread states.A quasiparticle-plus-rotor (QPR) model was applied to calculate the fragmentation in the doorway stage for the neutron deep-hole state in the Pd isotopes. A reasonable agreement between the calculation and the experimental results was obtained for the strength fragmentation, for the nucleus 101Pd. However, the large M1-E2 mixing ratio experimentally observed was not reproduced. 相似文献
11.
The threshold behaviour of pion production presented in our earlier work is successfully compared with the new SPEAR data. By using duality and sum rules we derive FT(π+)(x) ≈ FL(π+)(x) ≈ FT(π0)(x) ? FL(π0)(x) for x near 1. An accompanying results is for large s. 相似文献
12.
Victor Elias 《Physics letters. [Part B]》1977,68(4):335-338
The Callan-Gross relation is shown to be consistent with MIT-SLAC data for for x ? 0.33 in deep inelastic eN scattering, despite the fact that these data are taken in the large Q2 region where F1 and F2 individually exhibit scaling violation. Comparison is made with asymptotic freedom predictions, and color excitation is proposed to explain large values of at small x. 相似文献
13.
The variation of the conductivity of glassy Zr100?xCux alloys (x=50, 58, 67 and 71) in the temperature range 2–300 K is discussed in some detail. It is shown that the conductivity varies as √T for and T for the lower temperatures which is consistent with the predictions of a weak localization theory. Another strong temperature variation of the conductivity sets at the lowest temperatures which could be either due to interaction effects or due to electron scattering on the unstable ionic configurations. Some support to the latter effects is presented. 相似文献
14.
Negative-parity levels in the doubly even N = 82, Z nuclei, with 3.0 MeV ? Ex? 6.0 MeV are described in an extended unified-model approach, where neutron hole states in the Z = 50, N = 82 closed shell core, (i.e. ) are coupled to the low-lying levels (Ex ? 2.0 MeV) of the odd-neutron N = 83, Z nuclei. This particular configuration space of generalized neutron particle-hole states (GNPH) is particularly suited for describing negative-parity levels obtained in proton inelastic scattering through isobaric analogue resonances (IAR), corresponding to the N = 83, Z low-lying nuclear levels. Level schemes as well as partial decay widths and angular distributions are calculated and compared extensively with the available experimental data. Also spectroscopic factors, as well as wave functions, deduced from the experimental results are studied in detail. Thus in the cases of 136Xe, 138Ba, 140Ce, 142Nd and 144Sm, some of the important neutron particle-hole configurations can uniquely be determined in the energy region 3.0 MeV ?Ex ? 6.0 MeV. 相似文献
15.
W.A. Sterrenburg S. Brandenburg J.H. van Dijk A.G. Drentje M.B. Greenfield M.N. Harakeh H. Riezebos H. Sakai W. Segeth S.Y. van der Werf A. van der Woude 《Nuclear Physics A》1984,420(2):257-284
The nucleus 16F was studied via the 16O(3He, t) reaction at 81 MeV. Differential cross sections for many states were obtained and interpreted with DWBA calculations, using microscopic wave functions and an effective projectile-nucleon interaction. Proton decay to several states in 15O was observed and angular correlations for protons in coincidence with tritons detected at θ = 0° were measured. Several spin-parity assignments have been made. The distribution of isovector ΔL = 1 strength could be deduced. The analog of the giant dipole resonance ( is strongly excited. The magnetic quadrupole strength has two strong components, one low, at Ex = 0.424 MeV, and one high, at . Evidence is given for a proportionality between cross section and M2 strength for transitions to Jπ = 2? states, which possibly make the (3He, t) reaction a suitable tool for determining quantitatively isovector M2 (or Bij) strengths. 相似文献
16.
Excitation functions at θ = 90° have been measured for , , and , in the range E3He = 3–19 MeV. The first reaction has also been studied at θ = 40°. Excitation functions at 90° have also been measured for and for E3He = 19–26 MeV. Angular distributions have been measured for the first four reactions.For the most excitation functions, a broad peak is observed, several MeV wide, centred at about Ex≈ 20 MeV. Superimposed on this, in some cases, are narrower peaks, with width ≈ 1 MeV. Energies and widths have been extracted for all resonances.Cluster-model calculations have been carried out, using methods similar to those which have proved successful for low-lying states in A= 18–19 nuclei. No satisfactory correspondence with the present results was found. The shell model has been used to calculate Γ3He and Γγ for 1?ω excitations in the final nuclei. These generally show good agreement with the trends of the experimental data. The results are consistent with the excitation of the giant dipole resonance in 3He capture, but much more weakly than in proton capture. 相似文献
17.
R.F. Curl 《Journal of Molecular Spectroscopy》1973,48(1):165-173
The and transitions of the J = 7 levels of the ground state of CH4 have been observed by infrared-radio frequency double resonance using the 3.39 μ HeNe laser line. The transition frequencies are 423.02 ± 0.02 MHz and 1246.55 ± 0.02 MHz, respectively. Using these frequencies and the splitting of the E and F2 levels of the J = 2 state calculated from the molecular beam magnetic resonance spectra of Ozier, the centrifugal distortion constants are derived to be Dt = 132933 ± 10 Hz, H4t = ? 16.65 ± 0.2 Hz, and H6t = 10 ± 1 Hz. The J = 15 E(1) → E(2) microwave transition is predicted as 14150 ± 9 MHz. 相似文献
18.
A.D. Gocheva V.V. Gusev V.S. Melezhik L.I. Ponomarev I.V. Puzynin T.P. Puzynina L.N. Somov S.I. Vinitsky 《Physics letters. [Part B]》1985,153(6):349-352
Calculations are performed of the nonrelativistic energies of rotational-vibrational weakly bound states J = ν = 1 of ddμ and dtμ mesic molecules: and with an accuracy of 0.001 eV. With the relativistic effects and nuclear finite size corrections taken into account the result is: and . 相似文献
19.
We determine the invariant cross section for pp→ψ(3100)+X near x6=0 at NAL and ISR energies using the assumption that all large p⊥ single leptons originate from the ψ. We adequately reproduce the single lepton data, and by suitable extrapolarion in x6 ensure agreement with the NAL ψ production data (x6?0.3). The magnitude of the resulting ψ production cross section is, however, roughly a factor of 3 larger than that observed by the recent CCRS-ISR experiment. 相似文献
20.
J.L. Tholence 《Solid State Communications》1980,35(2):113-117
For the first time, the frequency dependence of Tf (temperature of the maximum of the a.c. susceptibility of spin-glasses) is shown to obey a Fulcher law . This is observed as well in the case of dilute alloys (or R.K.K.Y. spin-glasses : Mn, Fe, …) as for frustrated systems (Eu1?xGdxS, EuxSr1?xS …). For R.K.K.Y. spin-glasses, only in the case of a very small amplitude, Vo of the R.K.K.Y. interaction, this time dependence approaches an Arrhenius law. In the case of “frustrated” spin-glasses the concentration is the main parameter to determine the kind of frequency dependence of Tf. These properties are evidence for a glass-like phase transition in spin-glasses. The scaling of the frequency dependence of Tf with Vo is justified for R.K.K.Y. spin-glasses from present data. 相似文献