Francisco Javier Manjón Herrera

Effects of high-pressure on the structural, vibrational, and electronic properties of monazite-type PbCrO4

We have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of PbCrO4 (the mineral crocoite) at ambient and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. X-ray-diffraction, Raman, and optical absorption experiments have allowed us also to completely characterize two pressure-induced structural phase transitions. The first transition is from a monoclinic structure to another monoclinic structure. It maintains the symmetry of the crystal but has important consequences in the physical properties; among others, a band-gap collapse is induced. The second one involves an increase of the symmetry of the crystal, a volume collapse, and probably the metallization of PbCrO4. The results are discussed in comparison with related compounds, and the effects of pressure in the electronic structure are explained. Finally, the room-temperature equation of state of the low-pressure phases is also obtained.

Smartphysics: el uso docente del Smartphone para el desarrollo de competencias transversales

En este trabajo proponemos introducir nuevas practicas de laboratorio de fisica, y modificar algunas existentes, con el objetivo principal de que nuestros estudiantes desarrollen algunas de las competencias transversales establecidas por la Universitat Politecnica de Valencia (UPV), tales como pensamiento critico, comprension e integracion, aplicacion pensamiento practico, aprendizaje permanente, comunicacion efectiva, y trabajo en equipo y liderazgo. El instrumento que vamos a utilizar para alcanzar este objetivo es el telefono movil inteligente (smartphone), que operara tanto como dispositivo de medida como de almacenamiento de datos. Creemos que el uso del telefono movil sera un elemento motivador para el alumno ya que estan acostumbrados a su uso y ademas tendran la oportunidad de conocer nuevas aplicaciones de este dispositivo.