The title compound, C(16)H(12)O(6), is a common impurity of ortho-acetyl-salicylic acid (aspirin). The benzene rings form a dihedral angle of 81.9 (1)° while the acetyl and carboxyl groups form dihedral angles of 74.0 (1) and 26.4 (2)°, respectively, with the benzene rings to which they are bound. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds between the carboxyl groups...

zinc oxide (zno) nanoparticles were synthesized by spray pyrolysis method using an aqueous solution of zinc acetate at various concentrations from 5 to 25 wt%. the decomposition of precursor solutions was carried out at 800, 1000 and 1200ºc under different atomizing pressures. the crystal structure and morphology of synthesized nanoparticles were characterized by x-ray diffraction (xrd) spectro...

Several reviews concerning the EPR of the paramagnetic transition-metal ions in crystals are now available, either as periodic reports published in the Magnetic Resonance Review, or in books [1,2,3] and review papers [4, 5]. Such paramagnetic centers are usually observed in the as grown crystals, the paramagnetic state being the normal valency state of the impurity in the crystal-host lattice. ...

We report on the thermal conductivity of tin-doped bismuth between 50 mK and 27 K. A quantitative interpretation of the data is presented. At the lowest temperatures the electronic thermal conductivity dominates, but above 0.1 K lattice waves carry most of the heat. Below 1 K phononsare scatteredmostly by crystal boundaries, while near the dielectric maximum point defects are important. Their s...

In the first step, experiments on a single cerium or ytterbium Kondo impurity reveal the importance of the Kondo temperature by comparison to other type of couplings like the hyperfine interaction, the crystal field and the intersite coupling. The extension to a lattice is discussed. Emphasis is given on the fact that the occupation number n f of the trivalent configuration may be the implicit ...

Secondary ions mass-spectrometry and spreading resistance profiles in the layers of a ferromagnetic Si implanted with Mn has been studied. Czochralski Si wafers both nand p-type, of highand low-resistivity, as well as a float zone Si were implanted with impurity fluencies of (1 5) x 10 16 cm -2 . The Mn impurity was found to compensate acceptors in a high-resistivity p-Si and donors in a low-re...

The features of InAs quantum dots obtained on GaAs(001) single-crystal substrates by ion-beam sputtering were investigated. It has been shown that in the range of ion energies of 150 to 200 eV at a temperature of 500 °C and a beam current of 120 µA InAs quantum dots with average dimensions below 15 nm and a surface density of 1011 cm-2 are formed. The technique of controlled doping of InAs/GaAs...

Applying the Nakajima-Zwanzig method to the von Neumann equation of a system of interacting electrons and nuclei, etc., and evaluating the Pauli-Master equation according to RieckersStumpf, we obtain a system of reaction equations for electron-phonon-photon processes in a polar crystal. Further elaboration of these reaction equations leads to rate equations for electrons which include impurity ...

Angle-resolved photoemission is used to determine the change in the electronic states of Ni induced by doping with Fe and Cr. Well-defined spin and k states are selected using high energy and k resolution combined with single crystal alloys. Iron suppresses the mean free path of minority spins only, while chromium suppresses both spins and decreases the magnetic splitting. The strong variation ...

The title compound, C(18)H(10)O(4), has been isolated as an impurity in commercially available 6,11-dihydr-oxy-5,12-naphth-acenedione. The title compound exhibits yellow fluorescence in the solid state. The mol-ecule has crystallographic inversion symmetry and is planar, with an r.m.s. deviation of 0.031 (1) Å. The crystal structure is stabilized by C-H⋯O hydrogen bonds and π-π stacking inter-a...