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1.
Pb(Zr0.4Ti0.6)O3 film prepared by sol-gel spin coating on a Pt/Ti/SiO2/Si substrate is applied to ferroelectric capacitors with Pt or Ru as the top electrode. For the Pt/PZT/Pt and Ru/PZT/Pt ferroelectric capacitors, although with the same ferroelectric film, different top electrode materials incur different properties of PZT capacitors, such as fatigue, leakage, remanent and saturated polarization, except the similar crystal orientations of the PZT film. After 10^10 switch cycles, the remanent polarizations of the Ru/PZT/Pt and Pt/PZT/Pt capacitors decrease to 70% and 84%, respectively. The leakage current density of the latter increases obviously at positive bias after 108 switch cycles, compared with the former. Different materials for the top electrode bring different conditions at the PZT/top electrode interface. The influence of oxygen-vacancy concentration at the PZT/electrode interface and the influence of oxides of the electrode material at the PZT/electrode interface to charge injection can explain the difference of properties of the PZT capacitors with Pt or Ru as the top electrodes.  相似文献   

2.
An analytical method has been proposed for calculating the probabilities P i (2)(s) of existence of X-X, X−□, and □−□ pair interactions in the nonmetal sublattice of M 2tX2t−1 superstructures formed in strongly nonstoichiometric compounds MX y (MX y 1−y) and M 2X y (MXy/21−y/2) with a high content of structural vacancies □. The main characteristics necessary for the quantitative determination of the probabilities Pi(2)(s) as functions of the composition, degree of long-range order, symmetry, and structure type have been determined for all the known superstructures M 2tX2t−1.  相似文献   

3.
The process of reconstuction of the distribution profile of hole concentration in the p +n structure by the method of differential Hall measurements upon implantation of ions As+ (Е = 190 keV, D = 3.1014 cm-2, j = 0.025 μA/cm2) into epitaxial films Cd x Hg1–x Te for x ~ 0.2, with the initial electron concentration and mobility n = 1014 cm-3 and μ = 2∙105 cm2∙V–1∙s–1 is numerically simulated. The dependences of degree of reconstruction of the hole-concentration distribution profile on the depth of a shunting n-layer and magnitude of the magnetic field, at which the electrophysical parameters of the p +n structure are measured, are calculated. The dependence of the limiting magnetic field determining the magnetic-field range for measurements on the n-layer depth is found. It is shown that in calculations one should use the conduction values measured at the same magnetic fields as the Hall coefficients for determination of the holeconcentration distribution profile using the Petritz model.  相似文献   

4.
Ramanspectroscopyisapowerfultoolthatcanbeemployedtosolvecertainuniqueproblemsinchemical,biochemical,biophysical,andbiomedical...  相似文献   

5.
Properties of the Ag/Ni/p-GaN structure at different temperatures are studied by Auger electron spectroscopy, scanning electron microscopy and high resolution x-ray diffraction. The effect of Ag in ohmic contact on the crystalline quality is investigated and the optimized value of annealing temperature is reported. The lowest specific contact resistance of 2.5 × 10^-4 Ωcm^2 is obtained at annealing temperature of 550^o C.  相似文献   

6.
First-principles calculations are applied to investigate the effect of biaxial strain on the band gap of wurtzite Al x Ga1−x N. The band gap and band gap bowing parameter increase with compressive strain and decrease with tensile strain. The strain-induced changes in the band gap of Al x Ga1−x N are linear in the strain range of about −1% to 1% while the linearity is invalid out of the range. The linear coefficient B(x), characterizing the relationship between the band gap and the biaxial stress, with a quadratic form is obtained. The value of the band gap bowing parameter decreases from 1.0 eV for −2% strain to 0.91 eV for unstrained and to 0.67 eV for 2% strain.  相似文献   

7.
Five new bands of the f1Δ-a1Δ TiO system have been observed in emission between 17774.0 cm?1 and 19801.0 cm?1. Rotational and vibrational analyses of the 0-1, 1-0, 1-2, 2-1, and 1-1 bands, as well as a reanalysis of the 0-0 band, yielded the following molecular constants (cm?1):
  相似文献   

8.

Chronicle

Contents of the following issues of Opticheskiĭ Zhurnal (Journal of Optical Technology)  相似文献   

9.
The squeezing and higher-order squeezing properties of k orthonormalized eigenstates of the higher powers akqs(k≥3) of the annihilation operator of two-parameter deformed harmonic oscillator are investigated. It is found that the Nth-power squeezing [N=(m+1/2)k, m=0,1,2,…] can exist in the all of them when k is even.  相似文献   

10.
A measurement of the number of J/ψ events collected with the BESⅢ detector in 2009 and 2012 is performed using inclusive decays of the J/ψ. The number of J/ψ events taken in 2009 is recalculated to be(223.7±1.4)×10~6, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESⅢ software. The number of J/ψ events taken in 2012 is determined to be(1086.9±6.0)×10~6. In total, the number of J/ψ events collected with the BESⅢ detector is measured to be(1310.6±7.0)×106, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.  相似文献   

11.
High-resolution Fourier transform infrared spectra of natural trans-ClHCCHF and of its isotopologue trans-ClHCCDF have been recorded in the region between 700 and 1150 cm−1 with the purpose to analyze the ν11 fundamental of the main species and the ν10 of its deuterated compound. Both bands, of symmetry species A″, present c-type envelope absorptions. Beside the expected features, the K structure of the P(J), Q(J), and R(J) manifolds was resolved and identified; the assignment of the rovibrational transitions was extended up to J = 92 and Ka = 13 for the trans-35ClHCCHF and up to J = 86 and Ka = 10 for trans-35ClHCCDF. More than 2900 and 2700 lines for the main and deuterated species, respectively, were analyzed by a least-squares procedure and reliable spectroscopic molecular parameters were determined for both isotopologues.  相似文献   

12.
The problem of the estimation of high resolution comparative plots (αs method) is revised. Adsorption isotherms of Ar (T = 87 K) are simulated (GCMC) on the bundles of closed and opened multiwalled carbon nanotubes. Those materials are chosen in order to observe the influence of porosity on Ar adsorption, and consequently, on the comparative plots. The introduction of the structural heterogeneity (defects in the external and internal walls of osculating and separated nanotubes) is also studied. The monolayer and multilayer parts of adsorption are extracted from the total amount adsorbed for all studied adsorbents and the reference one (the bundle of the ideal 3-layered carbon tubes with very wide diameters). The significant influence of the distance between carbon nanotubes and defects (in the external and internal walls) is observed on the monolayer αs-plots. In the case of comparative plots calculated for the multilayer adsorption the differences are also visible; however, the expected linear dependence of the amount adsorbed on a porous solid plotted against the amount adsorbed on a reference nonporous solid (the layer-by-layer adsorption occurs on both solid surfaces) in a wide range of relative pressures is not observed. The obtained results demonstrate the complexity of αs method when both microporosity and surface heterogeneity are present. A comparison of isotherms shows that for the studied adsorbents Ar is sensitive to the appearance of the geometrical and structural defects, even at low coverage.  相似文献   

13.
The absorption spectrum of the ν2 fundamental band of the cis-conformer of the transient molecule HOPO, namely the terminal PO stretching mode, has been detected and measured using diode laser spectroscopy. The molecule was generated in a discharge flow system containing hydrogen and white phosphorus vapour (P4) and a trace of oxygen. The spectrum has the appearance of an a-type band of a near prolate asymmetric top. Above Ka = 5 the spectrum is perturbed and transitions terminating on these higher Ka levels were excluded from the fit. The vibrational frequency and rotational constants derived from the unperturbed parts of the spectrum are compatible with new high precision ab initio calculations reported here. A combined fit of the ν2 band and the ν4 band data, measured earlier, was carried out. The ν2 band origin was determined to be 1258.539525(32) cm−1, approximately 5.5 cm−1 higher than the matrix value.  相似文献   

14.
The number of J/ψ events collected with the BES0 detector at the BEPC/ from June 12 to July 28, 2009 is determined to be (225:3±2:8)×106 using J/ψ → inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.  相似文献   

15.
The spectrum of B2Σ+-X2Σ+ system of AlO has been recorded on BOMEM DA8 Fourier transform spectrometer at an apodized resolution of 0.05 cm−1. Nineteen bands of the Δv = 1, 0, −1, and −2 sequences of this band system have been analyzed for the rotational structure. Out of which seven bands, viz. 3-2, 4-3, 2-3, 3-4, 4-5, 5-6 and 6-7 have been analyzed for the first time. The rotational lines of these 19 bands along with 20 earlier analyzed bands, a total of 7200 lines, have been fitted in a simultaneous least squares fit. The study has resulted in determining more precise vibrational and rotational constants of the two states. Because of the high resolution employed it became necessary to invoke H0 and H1 coefficients, and a fifth order term to explain the anomalous spin-doubling observed in the v″ = 5, 6 and 7 levels of the X2Σ+ state.  相似文献   

16.
In high-energy nuclear collisions, the conventional Glauber model is commonly used to evaluate the contribution to J/ψ suppression originating from the inelastic interaction with colorless bound nucleons. This requires an effective value for the J/ψ-nucleon absorption cross-section which is larger than theoretically expected. On the other hand, multiple nucleon-nucleon collisions, mediated by color exchange interactions, excite their color degrees of freedom. We investigate the importance of this effect and find that these excited states provide a larger cross-section for J/ψ absorption. We conclude that the related corrections are important to explain the effective value extrapolated from experiment. Received: 6 November 2000 / Accepted: 5 June 2001  相似文献   

17.
The X2Π electronic ground states of NCO and CNO have been investigated by complete ab initio methods. The dependence of the Renner-Teller parameters, ? and , on the ab initio method and on the basis set have been studied. These parameters have also been compared to experimental data for NCO. The potential energy surfaces of the X2Π state have been determined by the MRCI method and the cc-pVQZ basis set for NCO and CNO. The rovibronic levels of both isomers have been calculated variationally up to approximatively 4000 cm−1 for J ? 5/2 and K ? 2, with the inclusion of the geometry dependence of the spin-orbit coupling. The agreement with experimental data obtained for NCO is remarkable. A similar accuracy for the ab initio rovibronic levels of CNO is expected since no experimental data exists for this isomer.  相似文献   

18.
Vibration-rotation transitions of diacetylene between the first excited states of the ν6 (CCH symmetric bending) and the ν8 (CCH antisymmetric bending) vibrations were observed with a Stark modulation microwave spectrometer. The rotational, centrifugal distortion and l-type doubling constants of the two vibrational states were determined as follows with 2.5 σ uncertainties in parentheses.
f1Δa1Δ
vBvDv (×106)BvDv (×106)
00.502277 (17)0.6411 (57)0.536168 (20)0.5938 (76)
10.499198 (32)0.630 (15)0.533227 (13)0.5971 (46)
20.530335 (26)0.636 (13)
ωe = 874.104 (4)ωe = 1018.273 (4)
ωeχe = 2.501 (4)ωeχe = 4.521 (4)
T′e?T″e = 19140.567 (8)
  相似文献   

19.
The Pt/Si/Ta/Ti multilayer metal contacts on 4H–Si C are annealed in Ar atmosphere at 600°C–1100°C by a rapid thermal processor(RTP). The long-term thermal stability is evaluated by aging the annealed contact at 600°C in air. The contact's properties are determined by current–voltage measurement, and the specific contact resistance is calculated based on the transmission line model(TLM). Transmission electron microscope(TEM) and energy-dispersive x-ray spectrometry(EDX) are used to characterize the interface morphology, thickness, and composition. The results reveal that a higher annealing temperature is favorable for the formation of an Ohmic contact with a lower specific contact resistance, and causes the rapid degradation of the Ohmic contact in the aging process.  相似文献   

20.
Laser excitation spectra of the A2Σ-X2Πi system have been recorded for 63CuS and 65CuS isotopic molecules with a single-mode dye laser operating in the region 17000–18000 cm?1. For highly overlapped sequences, use of a monochromator as a narrow band filter was necessary to allow rotational analysis. A simultaneous fit of all eight analyzed bands has led to the following spectroscopic constants for 63CuS (in cm?1):
Bv (MHz)Dv (kHz)qv (MHz)
ν64391.3230(84)0.582(154)2.4830(32)
ν84391.1921(94)0.594(179)2.4073(37)
  相似文献   

StatevTvBvDv × 106γvpvav × 106
A2Σ?017924.335 (7)0.17989 (4)0.177 (7)0.03853 (7)
X2Π121842.574 (7)0.18701 (4)0.163 (7)0.01496 (9)
0432.566 (6)0.18818 (4)0.162 (7)0.01508 (9)
X2Π321411.289 (7)0.18724 (4)0.184 (7)?0.96 (6)
00.18839 (4)0.160 (7)?0.11 (6)
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