Magnetic Properties of Eu0.9Yb0.1B6

Physics of the Solid State - The magnetic properties of substitutional solid solutions Eu0.9Yb0.1B6 have been investigated in the temperature range of 2–300 K in fields up to 5 T. The data...     

Study of ground states of <Superscript>3</Superscript>H, <Superscript>3,4,6</Superscript>He, <Superscript>6</Superscript>Li,and <Superscript>9</Superscript>Be nuclei by Feynman’s continual integrals method

The ground-state energies and the squared moduli of the ground-state wave functions are calculated for the ³H, ^3,4,6He, ⁶Li, and ⁹Be nuclei by Feynman’s continual (path) integrals method. The results are in satisfactory agreement with experimental data.     

Thermopower in quasi-two-dimensional (BEDT-TTF) m X n organic conductors

Thermopower of (BEDT-TTF) _m X _n organic conductors has been studied using a dedicated measurement technique in the temperature range of 4.2 to 300 K. It turned out that some features of the thermopower in quasi-two-dimensional metals, namely the presence of a peak in the thermopower of α-(BEDT-TTF)₂MHg(SCN)₄ and a plateau in κ-(BEDT-TTF)₂Cu(NCS)₂ in the temperature interval between 10 and 50 K, are probably due to the phonon drag effect. Similar temperature dependences of the Seebeck coefficient can be satisfactorily interpreted in terms of a simple model taking into account the real experimental curve of the phonon heat capacity versus temperature, C ∝ T ², which is not described by the Debye formula. One feature distinguishing organic superconductors from magnetically ordered metals is a stronger temperature dependence of the characteristic electron-phonon scattering time τ _e-ph(T). Phonon drag effects also determine the behavior of the thermopower in the (BEDT-TTF)₃Cl₂·2H₂O organic conductor, which is characterized by a metal-insulator transition at T∼150 K. An analysis of measurements of the conductivity and thermopower vs. temperature taken together indicates that the transition in this compound has a complex nature: first (at T∼150 K) a metal-insulator transition occurs, which produces an energy gap in the band spectrum, then at a lower temperature (T∼20 K) a transition to a charge-density wave state takes place. Zh. éksp. Teor. Fiz. 113, 323–338 (January 1998)     

(e,2e) electron spectroscopy of surfaces

Received: 21 March 1997/Accepted 12 August 1997     

Regularized quasi-classical approximation for Coulomb wave functions applied to describe nuclear reactions with heavy ions

Everywhere differentiable quasi-classical approximations in elementary functions are obtained for Coulomb wave functions. Their use for formulating boundary conditions for problems of scattering and fusion of heavy-ion nuclei is demonstrated.     

Spin-asymmetry in elastic scattering of low-energy electrons from ultrathin Au films on W(110)

We present joint experimental and theoretical results on the elastic scattering of spin-polarized electrons from an epitaxial Au film on a W(110) substrate in the energy range from 8 eV to 27 eV. A time-of-flight technique with a position-sensitive detector is applied to measure secondary emission spectra for spin-up and spin-down primary electrons in a specular geometry. The spin-asymmetry of coherently scattered electrons is obtained by selecting the diffraction spot on the detector. Regions of large asymmetries – with a maximum of about ?60 % – are identified for electron energies of about 14 eV. Relativistic multiple-scattering calculations produce spin-orbit-induced asymmetries which are in agreement with their experimental counterparts. They further reveal that large asymmetries are associated with high intensities. This offers the possibility of an efficient new spin polarimeter with a figure of merit of about 1.5 · 10^?2.     

Quasi-molecular states of neutrons in dinuclear systems and their effect on fusion of heavy atomic nuclei

The evolution of the wave functions of valence neutrons upon collisions of heavy nuclei having energies near the Coulomb barrier has been investigated by numerical solution of the multidimensional time-dependent Schrödinger equation. It is shown that even before overcoming the barrier by nuclei the wave functions of valence neutrons are extended to their volumes with occupation of quasi-molecular states. This process results in a significant effect of neutron transfers on nuclear fusion and, in particular, in a significant increase in the probability of subbarrier fusion for certain combinations of nuclei.