共查询到20条相似文献,搜索用时 31 毫秒
1.
The effect of the ratio of fluctuation field (Hf) to coercivity (Hc) on the temperature coefficient of coercivity [α(Hc)] was investigated for Co55Cr15.5Pt28B1.5/Co63Cr37/Cr, Co69Cr19Pt9Ta3/Cr, and Co86Cr10Ta4/Cr thin films (longitudinal recording media) with very small average grain volume (Vphy). α(Hc) increases markedly with increase in temperature between near 250 and 350 K for Co55Cr15.5Pt28B1.5/Co63Cr37/Cr thin films. α(Hc) is approximately proportional to the ratio Hf/Hc for all thin films, as in the case of advanced data backup tapes prepared from ultrafine particles. α(Hc) and the ratio Hf/Hc increase as Vphy decreases. Smaller Hf/Hc values are necessary for small α(Hc) values, which is very important for the thermal stability of high-density recording media with very small Vphy. 相似文献
2.
J.H.M. Mooy 《Solid State Communications》1981,39(12):1305-1309
Critical behaviour with dimensionality d = 2 has been observed for the 300 K antiferrodistortive phase transition in Al ur6(ClO4)3 and Ga ur6(ClO4)3 by means of the temperature dependence of the ESR parameter D. The systems exhibited d = 2 behaviour in the static critical behaviour for T<Tc?40 K for T>Tc + 40 K. From the ESR data including line width measurements the local order parameter relaxation rate ω1 has been obtained for various temperatures above Tc, with a lowest value of ω1 = 150 MHz at Tc + 15 K 相似文献
3.
N. A. Borovoĭ N. A. Kmetsinskaya V. F. Surzhko V. I. Shiyanovskii 《Optics and Spectroscopy》2002,93(3):345-350
The shape and relative intensities S α=I(α1s )/I(α1s ), S β=I(β1s )/I(β2) of the short-wavelength X-ray Lα1 and Lβ2 satellites arising from the radiative decay of the states corresponding to L 3 M 4,5 configurations were investigated experimentally for Hf, Ta, W, Re, and Os. It was established that, in the case of W, the values S α=2.5%, S β=4.2% are five to seven times larger than those for Hf and Ta, and by (30–60)% smaller than those for Re and Os. On the basis of the obtained values of S α,S β, as well as the observed two-component structure of the Lα1 and Lβ2 satellites, it is concluded that the Coster-Kronig L 1-L 3 M 5 transitions (CK) are allowed by the energy conservation law even for tungsten, and, starting with this element, they represent a major channel of generation of the states of LL 3 M 5 configuration. Possible features of such a process for the W atom are discussed in comparison with those for Re and Os. 相似文献
4.
The original theory of a proximity effect is proposed for the bi- and tri-layered system ferromagnetic metal/superconductor (F/S) in dirty limit. The F1/S/F2 trilayer is examined more closely. The distinctions in materials, in thicknesses of F layers (df1 and df2), in parameters interfaces, and in local environments of layers are considered among the causes of incommensurability of trilayer. The peculiar Tc(df1, df2) interference pattern is predicted for the F1/S/F2 systems. The reentrant superconductivity and possibility of the better observability of the spin-valve regime are discussed. 相似文献
5.
K.G.P. Sulzmann T.S. Lund D. Baxter 《Journal of Quantitative Spectroscopy & Radiative Transfer》1984,32(1):49-59
Shock-tube HeXe-laser absorption data at ωL=2850.633 cm-1 for CH3COOCH3 at 757≤T, °K≤1344, NO2at 412≤T, °K≤1859, andCH3at 1283≤T, °K≤1562 are presented. Approximate models are used for the effective spectral absorption coefficient of vibration-rotation lines for analytical representations of the results around atmospheric pressures. For CH3COOCH3, an equivalent Voigt-profile for an isolated line was adopted in order to account for a dependence on total pressure of the laser absorption coefficient. Shock-tube emission data at λ=6.890 μ(Δλ=0.197μ) forCH3COOCH3at 814≤T, °K≤1651 and for CH3at 1377≤T, °K≤1562 in the v4-fundamental of the H-bond bending mode of the CH3-group are well described at atmospheric pressures by approximations of just-overlapping-line models for polyatomic molecules. The adopted models are useful for concentration-time history measurements of methyl acetate, nitrogen dioxide, and methyl radicals behind shock waves. 相似文献
6.
The effect of hydrostatic pressure p on the low-frequency dielectric constant ? has been investigated for selected cyanides (NaCN, KCN) and cyanospinels [K2M(CN)4 with M = Zn, Cd, Hg and Rb2Zn(CN)4] for pressures up to 7 kbar In the low-pressure region (decreases monotomcally resulting in negative first-order pressure denvatives of the dielectric constant The second- and third-order pressure derivatives, however, proved to be positive in most cases Using the dielectric constant as a very sensitive probe we observed phase transitions from the cubic low-pressure phase to an orthorhombic (NaCN) resp trigonal (cyanospinels) high-pressure phase at the following transition pressures (for 293.2 K) 2 260 kbar for NaCN, 1 438 kbar for K2Hg(CN)4, 2 660 kbar for K2Cd(CN)4, 3 318 kbar for K2Zn(CN)4 and 0.690 kbar for Rb2Zn(CN)4 The transition temperature Tc, was found to increase strictly linear with pressure between 290 and 340 K at a rate of dTc/dp = 120 2 and 105 3 Kkbar?1 for K2Zn(CN)4 and K2Cd(CN)4, respectively. 相似文献
7.
We study the phase diagrams for the Ising model on a Cayley tree-like lattice, called Triangular Chandelier, with competing nearest-neighbour interactions J1, prolonged next-nearest-neighbour interactions Jp and one-level next-nearest-neighbour quadruple interactions Jl1. The phase diagrams display the multicritical points (the Lifshitz points) that are at nonzero temperature and many modulated phases. To perform this study, an iterative scheme similar to that appearing in real space renormalization group frameworks is established; it recovers, as particular case, previous work of Vannimenus extension result given by Ganikhodjaev and U?uz for k=3. At vanishing temperature, the phase diagram is fully determined for all values and signs of J1,Jp and Jl1. At finite temperatures several interesting features are exhibited for typical values of Jl1/J1 and −Jp/J1. 相似文献
8.
D.A. Steiner S.R. Polo T.K. McCubbin K.A. Wishah 《Journal of Molecular Spectroscopy》1983,100(2):453-454
The ν2 fundamental band of HNCO has been observed for the first time under a resolution of 0.015 cm?1. The band origin for this NCO antisymmetric stretching vibration is found to be at 2268.893 cm?1, rather distant from the previously reported value of 2274 cm?1. Nineteen subbands have been analyzed and term values for both ground and ν2 states with K up to 4 have been obtained. Effective rotational constants B and centrifugal distortion constants D and H have also been determined. Interactions are observed with 2ν4 + ν5 and ν3 + ν4. Large perturbations are observed for K = 0 and K = 1 levels of ν2. Transitions are also seen for three other vibrations, ν4 + ν5 + ν6, ν3 + ν6, and 2ν4 + ν6. 相似文献
9.
Arthur Williams 《Solid State Communications》1982,44(7):983-986
X-ray diffraction studies of La1?xAlx, La1?x(Al0.5Ga0.5x, La1?xGax and La1?xAux metallic glasses have been performed for x = 0.20, 0.24 and 0.28. Similarities in the radial distribution functions for these materials as well as other data suggest that these alloys are isostructural. Experimental data from different alloys have therefore been used to separate the three different pair distribution functions, which are then compared to dense random packing models and data for other metallic glasses. 相似文献
10.
M. Czajkowski E. Walentynowicz L. Krause 《Journal of Quantitative Spectroscopy & Radiative Transfer》1982,28(6):493-501
Quenching of excited Zn(41P1) and Zn(43P1) atoms by collisions with Ar, N2, H2, CO and CO2 has been investigated using methods of fluorescence spectroscopy. Mixtures of Zn vapor and quenching gases topped-up with Ar to maintain constant pressure were irradiated in a quartz cell with 2139 or 3076 Å resonance radiation which excited the 41P1 or the 43P1 state, respectively. The resulting resonance fluorescence and sensitized fluorescence were monitored in relation to the gas density. Intensity measurements yielded the following cross sections Qtot for the overall collisional deexcitation of the 1P1 state, Q3 for quenching of the 3P1 state, and Q13 for 1P1→3PJ excitation transfer.For N2: Qtot = 26, Q3 = 4.4, Q13 = 5.8; for H2: Qtot = 12, Q3 = 21, Q13 < 5 × 10-3; for CO: Qtot = 28, Q3 = 14, Q13 = 17; for CO2: Qtot = 76, Q3 = 23. All values are in Å2. 相似文献
11.
X-ray diffraction and Mössbauer measurements were performed on novelly synthesized La1?x Ba x FeO3?y (0≤x≤0.70). Two phases were found in the system. La1?x Ba x FeO3?y for 0≤x≤0.10 is an orthorhombic perovskite. La1?x Ba x FeO3?y for 0.54≤x≤0.70 is a cubic perovskite. La1?x Ba x FeO3?y for 0.10≤x≤0.54 consists of these two phases. 相似文献
12.
Willes H. Weber 《Journal of Molecular Spectroscopy》1980,79(2):396-415
The rigid-bender model is used to treat the large-amplitude, low-frequency, bending vibration ν7 of C3O2. Different parameterizations of the bending potential function are considered, and a simple two-term power series is found to give the best fit. With this parameterization, using a least-squares fit to energies and B values, the ν7 potential function is determined for the ground state as well as for the states in which ν2, ν3, ν4, ν6, 2ν6, ν1 + ν3, ν1 + ν4, ν2 + ν3, and 2ν2 + ν4 are excited. The excitation of other vibrations has in some cases a drastic effect on the ν7 potential. In the ground state the potential has a 29 cm?1 barrier at the linear position, in ν1 + ν3 the barrier increases to 79 cm?1, while in 2ν2 + ν4 the barrier vanishes. An equilibrium potential is determined by correcting the ground state potential for the effects of zero-point motion of the normal vibrations ν1, …, ν6. This potential has a 35.6-cm?1 barrier with a minimum at α = 11.14°, where 2α is the angular deviation from linearity. The model accurately predicts the quartic and sextic centrifugal distortion terms for the low-lying v7ν7l7 states. Second-order l-type coupling is included in the calculations of the quartic terms. The effects of this coupling, which are most pronounced for the ν7 ≥ 2 states, adequately explain the negative D term recently reported for the ν2 + 4ν70 state. 相似文献
13.
James A. Coakley 《Journal of Quantitative Spectroscopy & Radiative Transfer》1973,13(11):1237-1239
Chandrasekhar's equations for the functions S and T which represent the diffuse scattering and the diffuse transmission, respectively, of a beam of radiation by a planar atmosphere are invariant under the transformations S(τ1; μ, φ - μ0), φ0) exp (-τ1/μ0) = T(τ1; μ, φ; μ0, φ0) and T(τ1; μ, φ; -μ0, φ0) exp(-τt/μ0) = S(τ1; μ, φ; μ0, φ0). This relationship reflects the physical symmetry of radiative transfer in a planar atmosphere. It offers a simple method for obtaining the expression for S (T) when an analytical expression for T (S) exists. However, it does not appear to ofter any simplification of numerical solutions. 相似文献
14.
15.
The method of radiofrequency spectroscopy inside a CO2N2O laser cavity has been applied to the observation of pure nuclear quadrupole resonance, A1-A2 transitions and two-photon transitions of AsH3. From the assignment of these transitions some coincidences between laser lines and Δk = 3 transitions in the ν2 band and Δ|k ? l|; = 3 transitions in the ν4 band have been assigned. The quadrupole coupling constant eqQ and its rotational dependence χJ, χK and χd, and the spin-rotation constants CN and CK for the As nucleus have been determined for the ground state. The effective values of eqQ has been determined for the ν2 and the ν4 states. 相似文献
16.
The quadratic rotational constants A and B and torsional barrier V3, distortion parameters DJ, DK, and DJK, torsional distortion parameters Dm, DJm, and DKm, and barrier-dependence parameters F3J, F3K, and F3m have been determined for CH3CH3, CH3CD3, CD3CD3, and CH3SiH3 from the results of ab initio calculations done at the CCSD(T) level. Calculated values for the first six parameters are consistently within about 1% of experimental values, while the relative errors for Dm, DKm, F3J, and F3K are generally less than 20%. Calculation of the parameters DJm and DsJ is found to be more problematic, even with the application of vibrational averaging in the harmonic oscillator approximation. There is evidence that this is due to the influence of vibrational contact transformations in the experimental values. 相似文献
17.
《Solid State Ionics》2004,166(1-2):53-59
The monoclinic phase (P21/n) was formed for 0≤x≤0.6 and the NASICON-type rhombohedral phase (R3̄c) was obtained for the region 0.8≤x≤1.2 in the Li3−2xCr2−xTax(PO4)3 system. The activation energy for Li+ migration was ca. 0.45 eV for the monoclinic structure and ca. 0.36 eV for the rhombohedral structure. The maximum conductivity of 8.4×10−6 S cm−1 at 298 K was obtained for x=0.8 of the Li3−2xCr2−xTax(PO4)3 system. The conductivity of LiCrTa(PO4)3 was enhanced about three to five times by the addition of the lithium salt due to the improvement of the sinterablity. The maximum conductivity was 2.4×10−5 S cm−1 at 298 K for LiCrTa(PO4)3–0.2Li3BO3. 相似文献
18.
《Physics letters. [Part B]》1988,214(1):120-122
It is shown by numerical calculation that the best fit of the Fritzsch matrix to present data is found for values of the top-quark mass between 30 and 60 GeV, depending on the value adopted for the strange-quark mass. The value of mt that produces the best fit is very close to the geometrical scaling prediction of mt = mb(mc/ms) for current-quark masses. The residuals of the fit obey a surprising scaling rule, being functions of msmt rather than of ms and mt separately. 相似文献
19.
B.-S. Jeong S.J. Pearton Y.W. Heo D.P. Norton A.F. Hebard 《Journal of magnetism and magnetic materials》2008
Hall effect measurements were performed on epitaxial CoxTi1−xO2–δ thin films grown on (0 0 1) LaAlO3 by reactive RF magnetron co-sputter deposition. Magnetization measurements reveal ferromagnetic behavior in M–H loop at room temperature for CoxTi1−xO2–δ thin films for which x?0.02. An anomalous Hall effect was observed for Co0.10Ti0.90O2−δ films grown with the partial pressure of water P(H2O)=4×10−4 Torr or less. These films exhibit a positive ordinary Hall coefficient and a positive magnetoresistance. X-ray diffraction on films grown under these conditions shows evidence for TinO2n−1 phase due to the deficiency of oxygen. In contrast, Hall measurements taken for undoped and Co-doped TiO2 thin films grown under more oxidizing conditions show only the ordinary Hall effect with a negative Hall coefficient consistent with n-type conduction. For these films, the magnetoresistance was positive and increased monotonically with increasing magnetic field. The results suggest that Co-doped TinO2n−1 may be a dilute magnetic semiconducting oxide for which the carriers couple to the spin polarization. 相似文献
20.
《Journal of Physics and Chemistry of Solids》1987,48(12):1173-1184
Coherent potential approximation (CPA) calculations of the electronic structure of the III-V ternary alloys GaAs1−x Px, Gax In1−x As, Gax Al1−xAs, Gax In1−x P, and GaSb1−xPx are reported. Results are presented for the CPA self-energies, state densities, and band-bowing functions for these materials. The calculations utilize the sp3s1 bandstructures as input into the Chen and Sher CPA formalism. The present work is the first utilization of these bandstructures in CPA calculations for ternary alloys and the first CPA treatment ofGaSb1−xPx. In qualitative agreement with previous studies, the results of these calculations show that alloy disorder effects are small for GaAs1−xPx, of moderate importance for GaxIn1−xAs and GaxAl1−xAs, and relatively large for GaxIn1−xP. However, such effects are found to be significant for GaSb1−xPx, with this alloy predicted to be in the strong scattering regime. 相似文献