Showing papers by "Mildred S. Dresselhaus published in 1976"
TL;DR: In this article, an accurate model for the dispersion relations of the two coupled magnetic energy levels is developed, including the dependence of the magnetic energy on the magnetic field and on the wavevector component parallel to the magnetoreflection line shape of bismuth.
Abstract: We report here anomalies observed at high magnetic fields in the magnetoreflection line shape of bismuth $\stackrel{\ensuremath{\rightarrow}}{H}$ parallel to binary, bisectrix axes) and bismuth-antimony alloys $\stackrel{\ensuremath{\rightarrow}}{H}$ parallel to binary axis) and associated with Landau-level transitions originating from the lowest-quantum-number $j=0$ levels of the valence and conduction bands. Also reported are the corresponding Shubnikov-de Haas measurements made in steady magnetic fields up to 220 kG. To interpret these anomalous magnetoreflection line shapes an accurate model for the dispersion relations of the two coupled $j=0$ magnetic energy levels is developed, including the dependence of the magnetic energy levels on the magnetic field and on the wave-vector component parallel to $\stackrel{\ensuremath{\rightarrow}}{H}$. This model is applied to the interpretation of the Shubnikov-de Haas data and to a magnetoreflection line-shape calculation for the experimental conditions under which these anomalies are observed. The calculated line shapes successfully reproduce the large variety of observed line-shape anomalies as well as their relative intensities, thereby providing strong support for this description of the dispersion relations for the $j=0$ magnetic energy levels.
86 citations
TL;DR: In this paper, the E2g2 Raman peak for pure graphite is replaced by a doublet structure identified with in-plane carbon atom vibrations, and Raman peaks specific to the intercalate species are found at frequencies down-shifted from the stretching modes of the free intercalates molecules.
64 citations
TL;DR: In this paper, the temperature dependence of the d.c. conductivity in the c-direction of kish graphite is investigated and it is shown that both the magnitude and temperature dependence are similar to results reported in single crystal graphite, but qualitatively different from observations made in pyrolytic graphite.
39 citations
TL;DR: The first observation of symmetry-forbidden, first-order Raman scattering in the ferrimagnetic and antiferromagnetic phases of EuSe and in each of the magnetically ordered phases of Europium chalcogenides was reported in this paper.
34 citations
TL;DR: In this paper, magnetoreflection measurements are reported for residue compounds of graphite intercalated with up to 1.2 at.% Br. The observed magnetore-flection resonances show evidence for domains in which the electronic band structure and Fermi energy are only slightly dependent on bromine concentration.
12 citations