共查询到20条相似文献,搜索用时 31 毫秒
1.
J. Nishizawa K. Suto M. Kitamura M. Sato Y. Takase A. Ito 《Journal of Physics and Chemistry of Solids》1976,37(1):33-42
The deviations from the stoichiometric composition of HgTe and Hg0.82Cd0.18Te crystals have been controlled by heat treatment under Hg vapor pressure. The magnetic field dependence of the Hall coefficient always shows the presence of two different sets of electrons and one set of holes. A low mobility electron is shown to belong to the conduction band. Vapor pressure dependence of hole concentration in HgTe shows that the concentration of nonstoichiometric defects decreases with increasing Hg vapor pressure, but the hole concentration is always higher than the electron concentration. In the case of Hg0.82Cd0.18Te, the electron concentration exceeds the hole concentration at high Hg vapor pressures. The dependence of the conduction band electron mobility in HgTe upon carrier density shows that the scattering by holes and impurities is predominant. In Hg0.82Cd0.18Te, however, optical phonon scattering is dominant when the deviation from stoichiometry is small and the effect of residual impurities can be neglected, and scattering by holes is dominant when the hole concentration is over . 相似文献
2.
Results of measurements of conductivity, Hall and Seebeck coefficients of tellurium doped n-type crystals of platinum antimonide are presented. The Hall coefficient and the Seebeck coefficient undergo sign inversion twice, below and above room temperature. The detailed analysis of the experimental results revealed that below 200 K PtSb2 can be described by a simple conduction and valence band model. The energy gap Eg = (110?0.15 × T) (meV), the electron conductivity mass mnc/m0 = 0.35, acoustic phonon limited electron mobility 〈μa〉n = 3 × 106 T? () and mobility ratio 〈μa〉n/〈μa〉p = 0.4 are determined. However, at higher temperatures a more complicated valence band model is needed to account for the experimental results. The arguments for the existence of subsidiary valleys in the valence band are presented. 相似文献
3.
The processes with the cross sections not decreasing with energy become important at high energies. The simplest processes of this kind are γγ → Vi0Vj0 where V0 = ?0, ω, ?, ….. We calculate their cross sections in the high-energy small angle region s ? |t| ? μ2. The cross section γγ → ?0?0 at high energies (s ? 10 GeV2) exceeds those of γγ → ππ, ?+?? considerably. At (this is the characteristic energy for the VLEPP and SLC colliders) and , the ratio . 相似文献
4.
H. Ackermann T. Azemoon W. Gabriel D. Lüke H.D. Mertiens H.D. Reich G. Specht E. Ganssauge F. Janata D. Schmidt 《Nuclear Physics B》1978,133(3):397-407
We report measurements of kaon electroproduction from a hydrogen target carried out at DESY. The invariant cross section for the reaction ep → eK+ + anything is given as a function of the variables q2, W, x, p2⊥ and φ in the following region: . Finally we compare our data with a quark-parton model. 相似文献
5.
Takashi Tonegawa 《Solid State Communications》1981,40(11):983-986
The transverse spin pair correlation function pxn=<SxmSxm+n>=<SxmSxm+n> is calculated exactly in the thermodynamic limit of the system described by the one-dimensional, isotropic, spin-, XY Hamiltonian . It is found that at absolute zero temperature (T = 0), the correlation function ρxn for n ≥ 0 is given by , , where the plus sign applies when J is positive and the minus sign applies when J is negative. From these the asymptotic behavior as n → ∞ of |?xn| at T = 0 is derived to be with a = 0.147088?. For finite temperatures, ρxn is calculated numerically. By using the results for ?xn, the transverse inverse correlation length and the wavenumber dependent transverse spin pair correlation function are also calculated exactly. 相似文献
6.
The cross section for production of single photons in the process is calculated including selectron propagator and photino mass effects and is found to be significantly smaller than the local limit for selectron masses ? 35 GeV/c2. Numerical results for the cross section are obtained as a function of selectron masses for photino masses and electron beam energies E = 14.5, 25, and 35 GeV appropriate to PEP, PETRA, and TRISTAN, respectively. 相似文献
7.
With nuclear orientation on and in Os and NMR on oriented 189Pt and 191Pt in Fe electric and magnetic hyperfine splitting frequencies were measured. The nuclear moments are deduced to be: 189Pt: |μ| = 0.434(9) μN, Q = ?0.65(26) b; 191Pt: |μ| = 0.500(10) μN, Q = ?0.64(26) b; 195mPt: Q = +1.42(60)b. The negative spectroscopic ground-state quadrupole moments of 189Pt and 191Pt must be due to oblate ground-state deformations, thus indicating that the prolate-oblate phase transition in Pt is located at A < 189. 相似文献
8.
S. Fortier J.M. Maison P. Picot S. Galès E. Hourani J.P. Schapira 《Nuclear Physics A》1981,370(2):189-204
The 40Ca(α, 3He) reaction has been studied at 36 MeV incident energy. About fifty levels have been observed up to 7.1 MeV excitation energy and angular distributions were measured from 6–60° using a split-pole spectrometer. A local zero-range DWBA analysis has been carried out, and the deduced l-assignments and spectroscopic factors are compared with those obtained from previous neutron stripping experiments. Core-excited states in 41Ca with a [3? ? f7,2], [2+ ? f7,2] and [5? ? f7,2] component previously observed in inelastic scattering experiments, are selectively excited by the (α, 3He) reaction. Their angular distributions are compared with coupled-reaction-channel calculations, assuming a pure two-step reaction mechanism. The agreement between theory and experiment may be considered as rather satisfactory for a number of levels. In particular the levels and the high-spin states with are successfully described within the framework of the weak-coupling model. 相似文献
9.
10.
B. Niczyporuk T. Zełudziewicz K.W. Chen R. Hartung G. Folger B. Lurz H. Vogel U. Volland H. Wegener J.K. Bienlein R. Graumann J. Krüger M. Leissner M. Schmitz F.H. Heimlich R. Nernst A. Schwarz M. Scheer 《Physics letters. [Part B]》1981,100(1):95-100
We report the first observation of the decay . The 7 events seen yield a branching ratio B(?′→?π+π?)=(19±8)%. A consistent value of B=(26±13)% is obtained from the charged multiplicities of the ?′ and ? decays. Using these values we deduce Γtot(?′)=(31+10?8) keV and Bee(?′)=(1.8±0.5)%. Furthermore we estimate Γ(?′→gg?)=(10±5) keV in agreement with QCD predictions using vector gluons while one would expect 100 keV with scalar gluons. 相似文献
11.
J.C.D. Brand U.D. Deshpande A.R. Hoy S.M. Jaywant 《Journal of Molecular Spectroscopy》1983,100(1):143-150
The E-B (0g+-0u+) band system of Br2 has been investigated at Doppler-limited resolution using polarization labeling spectroscopy. Merged E state data for the three naturally occurring isotopes in the range vE = 0–16, expressed in terms of the constants for 79Br2, are (in cm?1) Y0,0 = 49 777.962(54), Y1,0 = 150.834(22), Y2,0 = ?0.4182(28), Y3,0 = 6.6(11) × 10?4, Y0,1 = 4.1876(28) × 10?2, Y1,1 = ?1.607(16) × 10?4, and Y0,2 = 1.39(39) × 10?8. The bond distance is , and the diabatic dissociation energy to . 相似文献
12.
The magnetic hyperfine splitting vM=|gμNBHF/h| of 196mAu (jπ=12?; configuration ¦(π(; as dilute impurity in Ni has been determined with nuclear magnetic resonance on oriented nuclei as 96.0(2) MHz. With the known hyperfine field BHF = ?264.4(3.9) kG corrected for hyperfine anomalies the g-factor and magnetic moment of 196mAu are deduced to be |g| = 0.476(7) and |μ| = 5.72(8) μN. Taking into account the known magnetic properties of and isomeric states in the neighbouring odd Pt, Au and Hg nuclei the structure of the 12? state is discussed. 相似文献
13.
Artemio Scalabrin Richard J. Saykally Kenneth M. Evenson H.E. Radford Masataka Mizushima 《Journal of Molecular Spectroscopy》1981,89(2):344-351
Laser magnetic resonance (LMR) for five rotational transitions, J = 4 ← 3, 5 ← 4, 7 ← 6, 8 ← 7, 9 ← 8, of the oxygen molecule 16O16O in its metastable state, a1Δg, v = 0, are observed using six fir laser lines. Taking the known values of the g factors, their zero-field frequencies are obtained as 340.0085(6), 424.9810(9), 594.870(1), 679.780(1), and 764.658(1) GHz, respectively. They are fit by , where B0 = 42.50457(10) GHz, D0 = 153.14(110) kHz, and q = 0.050(90) kHz. 相似文献
14.
The specific heat of liquid 3He has been measured from 4 to 300 mK. Even at very low temperature, it deviates from a pure γT behavior. The effective mass is in good agreement with previous results, but disagrees with recent measurements around TA. 相似文献
15.
We investigate single scalar lepton and scalar quark production processes at the Z0 peak. We find that a detectable number of these scalars should be produced at the SLC and LEP-I colliders even if their masses substantially exceed the beam energy E = mZ/2?45 GeV. 相似文献
16.
The Debye-Waller factor of hcp 4He at molar volumes Vm of 12.06 and 15.72 cm3 has been measured by neutron diffraction techniques. It has been found that for scattering vectors the Debye-Waller factor can be well represented by a simple Gaussian. The Debye temperatures, appropriate to the Debye-Waller factor, were found to be 99.73 K (Vm = 12.06 cm3) and 55.86 K (Vm = 15.72 cm3). No evidence was found of any forbidden reflections. 相似文献
17.
The emission spectrum of HCl+ has been measured and analyzed for four isotopic combinations. These analyses extend previous work and provide rotational constants for the v = 0–2 levels of the ground state and for the v = 0–9 levels of the excited state. RKR potentials have been determined for both states, although the upper state could not be fitted precisely to such a model. Calculated relative intensities based on these potentials demonstrated that the electronic transition moment must change rapidly with lower state vibrational quantum number. Although considerable caution should be exercised in applying the concept of equilibrium constants to the state, the following are the best estimates of these constants (in cm?1) for the state of H35Cl+: Be = 9.9406, ωe = 2673.7, Ae = ? 643.7, and . For the state of H35Cl: Te = 28 628.08, Be ~ 7.505, ωe ~ 1606.5, and . 相似文献
18.
V Malathy Devi B Fridovich G.D Jones D.G.S Snyder 《Journal of Molecular Spectroscopy》1983,97(2):333-342
Line strengths and self- and nitrogen-broadened half-widths were measured for spectral lines in the ν3 and ν2 + ν4 bands of 12CH4 and 13CH4 from 2870–2883 cm?1 using a tunable diode laser spectrometer. From measurements made over a temperature range from 215 to 297 K, on samples of 12CH4 broadened with N2, we deduced that the average temperature coefficients n, defined as , of the Lorentz broadening coefficients for the ν3 and ν2 + ν4 bands of 12CH4 were 0.97 ± 0.03 and 0.89 ± 0.04, respectively. A smaller increase is observed in line half-width with increasing pressure for E-species lines, for both self- and nitrogen-broadening, than for other symmetry species lines over the range of pressures measured, 70 to 100 Torr. 相似文献
19.
P. Fayet 《Physics letters. [Part B]》1982,117(6):460-466
We evaluate cross sections for the two processes e+e? → γ-photino-antiphotino, e+e? → γ-gravitino-antiphotino. In the local limit approximation they are proportional to (spin-0 electron) and (gravitino), respectively. I If spin-0 electrons have masses between 16 and , the γ-photino-antiphotino production cross section would be of the order of 0.4 to 0.1 pb at , with the cuts indicated in the text. Detecting this process is within the range of possibilities at PETRA. If no such signal is found the existence of light photinos coupled to spin-0 electrons lighter than , or to gravitinos lighter than , would be excluded. 相似文献
20.
S. Burzynski M. Baumgartner H.P. Gubler J. Jourdan H.O. Meyer G.R. Plattner H.W. Roser I. Sick K.-H. Möbius 《Nuclear Physics A》1983,399(1):230-240
We have measured 16O17O elastic cross sections at 22 MeV between 65°–140° to ± 1 %. The observed oscillatory interference between Coulomb scattering and the neutron transfer process is analyzed using exact finite-range DWBA. A model-independent value of is obtained for the coupling constant of the 1d neutron in 17O. We also present an analysis of data on magnetic electron scattering from 17O, which yields precise information on the magnitude and the radial shape of the neutron bound-state wave function. With this we relate the coupling constant to the spectroscopic factor and find S = 1.04 ± 0.11. We show that the magnetic electron scattering data alone yield S = 1.04 ± 0.10. Combining these results with earlier work we recommend and S = 1.03 ± 0.07 as best values. This spectroscopic strength corresponds to (91 ± 7) % of the full single-particle value. 相似文献