The anisotropy of conduction electron scattering in the noble metals

The main purpose of this paper is to bring together experimental results which have yielded some quantitative information with respect to the anisotropy of conduction electron scattering in the noble metals. It is found that from the ordinary transport properties, and in particular from analyses of the Hall effect and deviations from Mattheissen's rule, the assembled conclusions do not present a coherent picture, at least with regard to electron-impurity scattering. The results for scattering by phonons are more consistent. The advent recently of rather precise (～ 0·1%) specifications of the noble metal Fermi surfaces together with the knowledge of certain derivative properties over them makes possible more direct measurements of electron scattering. The application of experimental techniques which are more commonly associated with the field of ‘Fermiology’, and in particular the de Haas-van Alphen effect, to study conduction electron scattering more directly is an important theme of the present paper. Such direct experiments, which can yield local values of the electronic lifetime, τ (k), make possible a comparison between theory and experiment prior to the stage where the Boltzmann equation or its equivalent needs to be solved.     

The influence of many-body interactions on the de Haas-van Alphen effect

The de Haas-van Alphen (dHvA) effect, or Landau quantum oscillatory magnetization of metals, has been widely used to explore the single-particle aspects of electrons in metals with the aim of determining their Fermi surfaces. Its role in studying many-body effects in metals is less familiar, even though the influence of such interactions is well known. We present a general field-theoretic approach to this problem which shows that the paradigm for understanding the influence of many-body interactions in the dHvA effect should be shifted from the intuitively reasonable but potentially misleading arguments based on the electron self-energy on the real energy axis to an analysis of the self-energy along the imaginary energy axis. When viewed in this way, the dHvA effect assumes the role of a many-body self-energy filter in which the real part of the self-energy renormalizes the dHvA frequency while the imaginary part renormalizes independently the dHvA amplitude. We obtain a general theory for the dHvA effect in an interacting system which preserves the structure of the original non-interacting theory of Lifshitz and Kosevich. We then apply this extended Lifshitz-Kosevich theory to the analysis of several problems of interest, including electron-electron and electron-phonon interactions, heavy fermions and type II superconductors.     

De Haas-van Alphen studies of conduction electron scattering in dilute alloys of copper

Measurements of the Haas-van Alphen Dingle temperatures per atomic percent solute have been obtained for seven different cyclotron orbits in dilute alloys of nickel, germanium and gold in copper. The measured values have been inverted using a Fourier series representation for τ _k ^?1 to determine the variation of the local scattering rate over the Fermi surface for each species of solute.     

De Haas-van Alphen studies of conduction electron scattering in dilute alloys of copper

Measurements of the Haas-van Alphen Dingle temperatures per atomic percent solute have been obtained for seven different cyclotron orbits in dilute alloys of nickel, germanium and gold in copper. The measured values have been inverted using a Fourier series representation for _k ^–1 to determine the variation of the local scattering rate over the Fermi surface for each species of solute.     

De Haas-van Alphen effect studies in dilute alloys of silver and gold

De Haas-van Alphen experiments have been used to determine the scattering temperatures which characterize the [111] neck and belly extremal orbits in some dilute alloys of silver and gold. The relaxation time is anisotropic withτ _N/τ _B≃2 in both Ag(Au) and Au(Ag) when the scattering is dominated by the solute. This anisotropy is in the opposite sense to that observed in another homovalent alloy Ag(Cu) and to that observed in the presence of charged impurities.     

Comment on the observation of magnetoacoustic quantum oscillations in UBe13

The origin of previously reported magnetic quantum oscillations in UBe₁₃ is possibly due to Al inclusions. New measurements of the a.c. susceptibility show Al inclusions which result from the method of crystal growth using aluminium as flux. We discuss the distribution and form of the inclusions and compare our dHvA measurements with those of the -orbits of Al.     

Effect of a pulsed magnetic field on the transverse resistance of a layered superconductor

The field dependences of the transverse resistance of a single crystal of the layered superconductor Bi₂Sr₂CaCu₂O_y (BSCCO-2212) with T _c 0≃92 K are studied in magnetic fields up to 50 T in the perpendicular orientation H⊥(ab). It is established that in the resistive region the resistance is a power-law function of the field, and the temperature dependence of the barrier height for flux creep is obtained. It is found that in a wide temperature range, 50–125 K, the transverse magnetoresistance of the crystal in the normal state and under conditions of superconductivity suppression by a strong magnetic field is negative and can be approximated by a linear law with a temperature-dependent slope. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 5, 420–425 (10 September 1998)