Results 1 - 10 of 278
Results 1 - 10 of 278. Search took: 0.021 seconds
|Sort by: date | relevance|
[en] In this work, superconductors that contain paramagnetic ions which only interact with the superelectrons via electromagnetic fields are considered. We postulate that when these materials are superconducting, a consequence of the phase coherence of the superelectrons is that if the external field is changed, after equilibrium is reached, there is no net heat produced or absorbed by the paramagnetic ions. We find that in high magnetic fields, when the susceptibility (χ) of the paramagnetic ions is such that 0≤χ<<1, the superconductor behaves like a standard type II material and for χ>>1, the material behaves ferromagnetically such that there is a square flux line lattice. The magnetic phases present for different values of χ and magnetic field are described, and experimental evidence for them is provided. (author)
[en] In this paper, the history of the discovery of the linear magnetoresistance in metals by Kapitza from 1928-1929 and its explanation are described. Actually, Kapitza discovered two different phenomena. One of them, the linear magnetoresistance at classically large magnetic fields in polycrystalline samples of metals, having open Fermi surfaces, was explained by Lifshits and Peschansky in 1958. The other phenomenon is the quantum linear magnetoresistance appearing in metals, or semimetals, with a small concentration of carriers and a small effective mass, when only the lowest Landau band participates in the conductivity. Manifestations of this unusual phenomenon in different materials are described
[en] The problem of the galvanomagnetic properties of composite materials is formulated for a lattice model. The effective galvanomagnetic characteristics of a weakly heterogeneous lattice are determined in the quadratic approximation in the deviation of local conductivity tensor (r) from average value <>. In the case of a low concentration (c ≪ 1) of “defect” bonds, effective conductivity tensor e of a binary lattice model is calculated in the c-linear approximation. Effective medium method equations are derived for the formulated lattice problem, and the results are compared with the results obtained in a continuous medium model.
[en] In order to understand theoretically in a better way the striking experimental behavior of the galvanomagnetic effect common to most of metals, a study is presented for a model of circularly cylindrical Fermi-surface on the basis of the Schockley-Chambers tube integral of electrical conductivity tensor. Two-kinds of orbits, i.e., closed and open orbits are posssible for this model. The concrete function-forms of the magnetoresistance tensor are found for both low and high magnetic fields, and also both closed and open orbits. The behavior of the functions is quite similar to those experimentally observed in most of metals. (Author)
[en] Both the magnetic depolarization of the spontaneous emission from self-aligned states and the discharge galvanic reaction are measured simultaneously in a magnetic field. The observed galvanic peak is ascribed to magnetic destruction of self-aligned ensembles of atoms. This presents galvanic manifestation of coherent conductivity. (letter to the editor)