共查询到20条相似文献,搜索用时 46 毫秒
1.
We have measured the resistivity of Mg and Mn up to 0.5 at. % impurity concentration between 0° and 100°C. The results for the resistivity for both systems can be analysed within one generalized model in which spinfluctuations as well as changes in the electron-phonon interaction are considered. For Mn a calculation of the impurity contribution to d?/dT is attempted. For Mg there are indications that the superconducting Tc will increase with Mg concentration. 相似文献
2.
R. Vaccarone A. Morozzo della Rocca A. Pilot F. Vivaldi C. Rizzuto 《Solid State Communications》1973,12(9):885-889
Measurements on the superconducting critical temperature Tc and critical field, Hc, of Cr and Mn alloys, down to 0.037°K are presented.The variation of Tc with increasing concentration depends strongly on Tcp/θ, with θ a characteristic temperature, while effects of Hc are similar to previously studied alloys. 相似文献
3.
T.G.M. Kleinpenning 《Journal of Physics and Chemistry of Solids》1976,37(10):925-928
Electrical resistivity, thermoelectric power and current noise were measured on Li-doped MnO single crystals in the temperature range from 300 to 1000 K. Below 700 K the crystals are p-type and the activation energy of the resistivity is 0.75 eV. Around 700 K the activation energy changes from 0.75 to 1.25 eV owing to a change from p- to n-type conduction. The depth of the Li acceptor is found to be 0.65 eV. From resistivity and thermoelectric power data it is concluded that the bandgap in first approximation can be written as Es(T) = Eo ? γT between 750 and 1000 K, with Eo = 1.9 eV and γ = 6 × 10?4 eV/K. The current noise spectra show noise. The magnitude of the noise is strongly temperature dependent. From the noise data it is deduced that Eo = 2.2 eV and γ = 10?3 eV/K in the temperature range 430–700 K. 相似文献
4.
P. Steiner G.N. Beloserskij D. Gumprecht W.V. Zdrojewski S. Hüfner 《Solid State Communications》1973,13(9):1507-1512
Mössbauer effect measurements of the Fe: system are reported which yield the local susceptibility of the Fe ions. At high temperatures (T ? 10°K) a Curie Weiss law with θ1 = 9.8°K is observed, whereas at low temperatures the Curie Weiss temperature is θ2 = 0.45°K. In both temperature regimes the local susceptibility is a linear function of the total susceptibility. In addition below 4°K the local magnetization is a linear function of the total magnetization up to external fields of 60 kG. 相似文献
5.
Measurements are presented of the thermopower of three concentrated Cr (0.9, 4.9 and 10.6 at.%Cr) alloys between 4 and 500°K. Considerable differences are observed in the thermopower compared with Fe alloys in a similar concentration range. Possible reasons for these differences are discussed in terms of current ideas on spin glasses and the pair model of Matho and Béal-Monod. 相似文献
6.
A.H. Thompson 《Solid State Communications》1973,13(11):1911-1913
The superconducting intercalation complex TaS2(pyridine) has received considerable attention as a prototype of two dimensional superconductivity. In this material we have detected a substantial, anisotropic magneto-resistance 11 K° above the superconducting transition and an anisotropic logarithmic resistivity rise below 20°K. The resistively measured superconducting transition temperature is also anisotropic. Tc is the lowest when the current is perpendicular to the layers. 相似文献
7.
A reanalysis of the resistometric data obtained by Takamura on quenched -Zn yields a vacancy-solute binding enthalpy considerably less than Takamura's estimate and more in line with the results of annealing experiments. The value obtained, 0.08 eV, is still about four times larger than estimates from positron annihilation experiments. 相似文献
8.
K. Winzer 《Solid State Communications》1975,16(5):521-524
The electrical resistivity of the system has been measured in the temperature range 0.04–300 K. The alloys show a Kondo minimum at about 20 K and a strong increase of the resistivity with decreasing temperature. The low temperature increase of the resistivity due to the Kondo effect of a sample containing 1, 2 at.% is about half as large as the room temperature resistivity of LaB6. The Kondo temperature TK of was found to be 1.1 ± 0.2 K by comparison of the experimental results with theoretical predictions of the resistance anomaly associated with the formation of the spin-compensated state. 相似文献
9.
It is shown that the pseudoscalar ηc and “ηc” (ηb and “ηb”) with M ≈ 2.80 and 3.51 GeV (9.17 and 9.88 GeV) can be predicted by using the radial mixing model, where the “ηc” and “ηb” are the excited 0- states in the and systems, respectively, and the former would correspond to the observed 0- meson with M ≈ 3.45 GeV in charmonium. 相似文献
10.
Angular distributions of the differential cross section and the three tensor analyzing powers were measured for the reactions 117Sn(, p)118Sn and 119Sn(, p)120Sn at Ed = 12 MeV. In addition, excitation functions of the tensor analyzing power T20 were measured at proton lab angles of 0° and 5° for energies ranging from 10 to 12 MeV. At forward angles, the tensor analyzing powers for the ground state (ln = 0) transitions are more than an order of magnitude larger than the predictions of distorted-wave calculations which neglect the deuteron D-state. Qualitative agreement with the measurements is obtained when the D-state is included. 相似文献
11.
The vector polarization transfer coefficient Kyy′ and the tensor analyzing power Azz have been measured for the 2H()3He reaction at θ = 0° over an incident deuteron energy range from 1 to 15 MeV in 0.5 MeV steps. The results agree with the previous 2H()3He measurements of Simmons et al. and are nearly identical to the 2H()3H measurements of Clegg et al. in the region of overlap. The present results provide an accurate and complete set of the observables necessary to use the 2H(,)3He reaction as a source of polarized neutrons. 相似文献
12.
In reactions such as e → anything, N → anything, the final state (neglecting secondary isospin violating decays) is customarily supposed to have isospin zero or one. We show that for such states the average fraction (X) of the energy carried away by neutral pions is bounded by , when I3 = 0 (e.g., for ee, pp, nn) and by , when I3=±1 (e.g., for pn or np). 相似文献
13.
H.W. Atherton B. French J. Skura J. Böhm J. Cvach M. Jireš J. Sedlák V. Šimák J. Žaček 《Nuclear Physics B》1976,113(3):378-394
577 events from annihilations at 5.7 GeV/c are analyzed. Single-particle spectra are studied and an effective matrix element in the form Πi=14 exp(?BpTi2) is determined. The rates for production of ?° and f0 mesons are estimated and the influence of resonances on the angular distributions of pions and dipions is investigated. Transverse momenta correlations can be explained using peripheral phase space. 相似文献
14.
Magnetic structure amplitudes in Ni1-xCrx alloys (x = 0.023 and 0.034) are measured using the polarised neutron diffraction technique. The structure amplitudes are analysed using the projection operator formalism. In this framework a new approach for defining local site moment, diffuse moment and asphericity in the site moment are discussed. A detailed multiband Coherent Potential Approximation (CPA) calculation for ferromagnetic Cr alloys using the Hubbard Hamiltonian with realistic parameters is discussed. The results of these calculations are compared with the existing bulk measurements like magnetisation and transport properties. The evolution of site moment and its asphericity with impurity concentration are obtained and compared with the present polarised neutron results. 相似文献
15.
The interference term between electron-phonon and electron impurity scattering has been evaluated for Cd and Mg and found to be negative, in agreement with experiment. It is shown that measurements on single crystal should give valuable information. 相似文献
16.
The resistivity and thermopower of dilute Cr alloys (21 resp. 32 atppm Cr) was measured between 1.3 and 15 K. Due to a special preannealing treatment the resistivity of these samples showed peculiar interaction effects below about 3 K. Low temperature reactor irradiation strongly increased the curvature of the anomalous resistivity. The results are discussed using the theory of Matho and Béal-Monod. 相似文献
17.
The microwave spectra of the d3 species of intramolecularly hydrogen-bonded 2-aminoethanol (ODCH2CH2ND2) as well as the d3-O18, d3-N15 and three d2 isotopic forms have been studied. The rs O-(D)?N distance of 2.8027(5) Å in the d3 species is 0.0058(7) Å shorter than the O-(H)?N distance found earlier for the d0 species (R. E. Penn and R. F. Curl, Jr., J. Chem. Phys.55, 651–658 (1971)). The anomalous rs structural parameters and ∠COH = 103.7°, when corrected for the systematic error caused by the O?N “shrinkage” upon deuteration, become 1.00 Å and 108°, respectively. 相似文献
18.
P. Benkheiri J. Boucrot B. Bouquet P. Briandet B. DAlmagne C.Dang Vu B. Eisenstein A. Ferrer P. Fleury B. Grossetête G. Irwin A. Jacholkowski A. Lahellec H. Nguyen P. Petroff F. Richard P. Rivet G. De Rosny H. Yoshida 《Physics letters. [Part B]》1977,68(5):483-486
From the study of the reaction using a fast proton (pF) trigger device in the CERN Omega spectrometer, we find evidence for two narrow states produced mainly in association with a Δ° (1232) and a N° (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M = 2020 ± 3 MeV, Λ1 = 24 ± 12 MeV and M2 = 2204 ± 5 MeV, Λ2 = 16?16+20 MeV. Our data are consistent with a small production of the narrow ~ 1935 MeV resonance already reported. Production cross sections for these new resonances are given. 相似文献
19.
We have made magnetostriction measurements on dilute Yb and Tb monocrystals at low temperatures. The shape magnetostriction follows the sign of the quadrupolar Stevens factor αJ of the earth but, in contrast to our recent results on silver-rare earth dilute alloys, the 〈001〉 and 〈111〉 effects have opposite signs. We obtain very good agreement between experiment and calculations based on the known cubic crystal-field parameters and we estimate the ion-lattice coupling parameters. The volume magnetostriction is positive, but very small, about two orders of magnitude smaller than the shape effect. 相似文献
20.
L.N. Abesalashvili N.S. Amaglobeli I.V. Boguslavsky J. Chýla J. Cvach S.V. Dzhmukhadze I.M. Gramenitsky I. Herynek U.A. Kiselevich I.A. Korzhavina A.M. Khudzhadze G.O. Kuratashvili R. Lednicky S. Ljung G. Martinska I.L. Melnichenko S.Ya. Nikitin R. Orava Z.M. Zlatanov 《Physics letters. [Part B]》1974,52(2):236-238
The multiplicity distribution for 11558 events in interactions at 22.4 was analyzed. The average charged multiplicity 〈nch〉 for inelastic events was found to be 4.69 ±0.05 and . The early KNO scaling of normalized topological cross sections has been tested. 相似文献