Computational modelling of intrinsic defects in the orthosilicates YSiO and LuSiO.

Atomistic computer modelling techniques were applied to study the intrinsic defects in the YSiO (YSO) and LuSiO (LSO) structures at 0 and 300 K temperatures. The approach used is based on the interatomic potentials model and lattice energy minimization. A set of potential parameters were obtained by empirical adjustment and reproduced the lattice parameters with values better than 0.

Mechanism of X-ray excited optical luminescence (XEOL) in europium doped BaAl2O4 phosphor.

This paper reports a luminescence mechanism in Eu-doped BaAl2O4 excited with monochromatic X-rays (also known as X-ray excited optical luminescence - XEOL) from synchrotron radiation. The material was prepared via a proteic sol-gel methodology. The X-ray absorption near edge structures (XANES) at the Ba LIII- and Eu LIII-edges exhibit typical absorption spectra.

Multi-photon excited coherent random laser emission in ZnO powders.

We report the observation and analysis of anti-Stokes coherent random laser (RL) emission from zinc oxide (ZnO) powders excited by one-, two- or three-photon femtosecond laser radiation. The ZnO powders were produced via a novel proteic sol-gel, low-cost and environmentally friendly route using coconut water in the polymerization step of the metal precursor. One- and two-photon excitation at 354 nm and 710 nm, respectively, generated single-band emissions centred at about 387 nm.