P. de la Mora

On the structure of lithium peroxide, Li2O2

The two published lithium peroxide structures, both ascribed to the hexagonal P6 space group, were subjected to reinterpretation, and another more symmetric structure, now belonging to the P6(3)/mmc space group, was found. Detailed density-functional quantum mechanical calculations and crystal structure optimizations were carried out on both structures and the energetic arguments obtained therewith helped to rule out one of them.

Anisotropy of optical and transport properties in the a-b plane of the high temperature superconductor YBa2Cu4O8

Abstract The anisotropy within the a-b plane of YBa2Cu4O8 has been studied on single crystal platelets by optical and electron transport measurements. The optical investigations include polarized reflectivity measurements at room temperature for photon energies between 0.5 and 4 eV and a direct measurement of the ratio of the reflectivity coefficients r b r a . The anisotropy of the electrical resistivity has been determined from AC van der Pauw measurements using the Montgomery formalism for anisotropic materials. The optical reflectivity spectra are dominated by Drude-like free electron contributions with plasmon energies of 2.8 eV and 1.67 eV for the electrical field vector along the b- and a-axis, respectively. The electrical resistivity displays an anisotropy of a factor of about 3. The superconducting transition temperature (midpoint of the resistivity drop) is 76 K. Contrary to YBa2Cu3O7, clear deviations from linear temperature dependences of the resistivity are observed in the normal state of YBa2Cu4O8. An extrapolation of the linear (normal) part gives zero resistance at 36 ± 2 K and not 0 K. The observed anisotropies are compared with results of a tight binding calculation.

Magnetic behavior of the Bi2−ySryIr2O7 pyrochlore solid solution

The temperature dependence of magnetic susceptibility of the Bi

Theoretical study of intradimer mechanism for diamond growth over diamond (100)

_{2-y}

On the limits of fractal surface behaviour in silica. A virtual adsorbates simulation

Sr

Reactivity analysis in diamond surfaces with a density functional calculation

_{y}

Electronic Structure of LaBO 3 (B=Mn,Fe,Co,Ni,Cu) Perovskites and La 2 NiO 4

Ir

Intensities of emission and absorption in Mössbauer spectra

_{2}

High-Pressure and Electronic Band Structure Studies on Mo_{2}BC

O

Electron dynamics of transition metal compounds studied with resonant soft x-ray scattering

_{7}