Showing papers in "Solid State Communications in 1988"

TL;DR: Amorphous carbon nitride thin films have been grown by plasma decomposition of a feedstock of CH4 and N2 as mentioned in this paper, and the optical absorption and photoluminescence spectra show that nitrogen incorporation decreases the bandgap and increases the structural order of these thin films.

TL;DR: In this article, the superconducting and normal state properties of compounds in the series Y1−xMxBa2Cu3O7−δ for 0 ≤ × ≤ 1 and Y 1−x MxBa 2Cu 3O7 −δ in the limited region of solubility 0 ≤ ≤ ≤ 0.5 have been investigated by means of X-ray diffraction, electrical resistivity ϱ, and magnetic susceptibility χ measurements.

TL;DR: In this article, the Amplitude Mode Theory worked out for obtaining a unified interpretation of the vibrational spectra of Polyacetylene can be reformulated in a simpler and more complete way in terms of straightforward concepts of moleculare dynamics.

TL;DR: In this paper, the structure of orthorhombic YBa2Cu3O7 was refined in the temperature interval 5-320K, to an accuracy higher by a factor of about two compared to previous refinements.

TL;DR: In this paper, the structures of two new superconductors were determined from their X-ray powder diffraction patterns, which are members of a new structural type: intergrowths of two BiO sheets with n (n = 1,2,3…) copper oxide perovskite-like layers.

TL;DR: In this paper, the full surface phonon dispersion curves of graphite (0001) over the entire energy region and the entire Brillouin zone along the ΓM direction have been determined for the first time by using electron energy loss spectroscopy.

TL;DR: In this paper, the compound of formula YBa 2 Cu 2.7 Fe 0.3 O 7.13 has been analyzed by neutron and electron diffraction techniques, and the results indicate that Fe 3+ is present in tetrahedral coordination and Fe 4+ in pyramidal and octahedral coordination.

TL;DR: In this paper, a d.c.-sputtering techique was employed to produce thin films of YBa2Cu3O7 on SrTiO3, MgO, Al2O3 and oxidized Si substrates.

TL;DR: In this paper, the variation of Raman and infrared spectra of the new high T c superconductors with oxygen content was studied and it was shown that the Raman peaks associated with Cu-O stretching vibration (502 cm −1, x=0) and Ba-O vibrations (154 cm − 1, x = 0) decrease in frequency when oxygen is removed.

TL;DR: In this article, the magnetic susceptibility measurements of the magnetoplumbite-like compound SrCr 8 Ga 4 O 19 showed that no magnetic phase transition occurs up to T = 4.2K in spite of very high antiferromagnetic interactions making apparent a very high degree of magnetic frustration (O/Tg 117).

TL;DR: In this article, the frequency, width, and intensity of the 1320 cm−1 peak near and above the Neel temperature (960 K) of α-Fe2O3 was investigated.

TL;DR: In this paper, the effects of the superconducting critical state with pinning and depinning of fluxons during a modulation cycle have been investigated, and it was shown that these effects are due to the properties of the critical state.

TL;DR: In this paper, a narrow ballistic constriction of finite length in a two-dimensional electron gas is modelled by assuming that the lateral confining potential defining it is parabolic and uniform along the channel.

TL;DR: The electronic and magnetic properties of the ceramic superconductor YBa2 (Cu1-xFex)3O7-δ with x = 0.067 have been studied microscopically by Mossbauer technique.

TL;DR: In this paper, the Raman spectra of diamond-like amorphous carbon (a-C) films were measured as a function of the excitation wavelength and a broad shoulder band at around 1400 cm-1 was observed in the spectra excited by the 5145 A line.

TL;DR: In this article, the electron wave guides are fabricated from high and low mobility GaAs-AlGaAs wafers and the background average resistance revealed quite different behavior in both samples.

TL;DR: In this paper, high-resolution neutron powder diffraction has been used to determine the crystal structures of YFe11Ti and YFe10Ti intermetallic compounds, and the temperature dependence of the magnetic anisotropy from 293 to 78 K was measured by the singular point detection technique.

TL;DR: A detailed study of the superconducting properties and crystal symmetry of YBa2Cu3Ox as a function of oxygen content (x) is presented in this paper, where it is shown that the orthorhombic to tetragonal phase transition coincides with a loss in superconductivity for samples prepared both by quenching from high temperature and samples prepared by deoxygenation at low temperature.

TL;DR: In this paper, a new type of stretch-aligned, iodine doped polyacetylene, yielding a room temperature conductivity σ of about 80 000 ω −1 cm −1.

TL;DR: In this paper, it has been concluded that the cation mobility is much enhanced by the strongly coupled rotational motion of the translationally static sulphate ions, which has been coined the paddlewheel or cogwheel mechanism.

TL;DR: In this article, a unit cell 2ac x ac x 3ac (ac being the basic perovskite subcell parameter; ac≅3.8A) is proposed together with a structural model.

TL;DR: In this article, a body centered tetragonal substructure related to the Aurivillius phases, with two lamellae per unit cell, has been shown to have incommensurate long period modulated superstructures, presumably induced by the misfit between the BiO layers and perovskite-like layers.

TL;DR: In this paper, an analysis of temperature dependences of AC susceptibility measured on bulk cylindrical samples of high-T c superconductors allowed to introduce a shielding current density model presented in the paper.

TL;DR: In this article, two structural arrangements have been shown to exist for the Perovskite-like compound BaBi 0.5 3+ Bi 5+ O 3 by powder neutron diffraction data.

TL;DR: In this article, the compositional variation of saturization magnetization and Curie temperature for Ni1−y−xZnxCuyFe2O4 where x = 0.0, 0.6, 0., 0.8, 1.0 for y = 0 and x =0.2 have been reported.

TL;DR: In this paper, the Raman spectra of highly oriented crystals of Bi2Sr2CuO6+δ and Bi2 Sr2CaCu2O8+ Δ were reported and a factor group analysis of the k = 0 phonons was given.

TL;DR: In this paper, a new model for the Fermi surface of LaB6 is proposed, which consists of spherical balls at X points connected by the short necks, instead of the slender necks previously considered, and small ellipsoid-electron-pockets which are elongated along the Σ axes and overlap on the necks.

TL;DR: Mossbauer spectroscopy of 57 Fe in both tetragonal and othorhombic phases of YBa 2 (Fe x Cu 1− x ) 3 O 7− δ, with x = 0.01, 0.02 and 0.10, at temperatures 4.2 K, 75 K, 90 K, and 300 K have been performed as mentioned in this paper.

TL;DR: In this paper, the authors report Raman and far infrared spectra of the semiconducting (O6) defect perovskites MBa2Cu3O6 and compare them to the spectra found in the high Tc superconductors (O7).

TL;DR: In this article, the crystal and molecular structure of BeH 2 was determined from high-resolution powder diffraction data obtained at a synchrotron radiation source, based on a network of corner-sharing BeH 4 tetrahedra.