La Enseñanza explícita de la pronunciación: creencias de los profesores y sus repercusiones en el aula de E/LE

En este trabajo me propongo analizar las creencias de un grupo de profesores de español como lengua extranjera acerca de la importancia de la enseñanza explícita de la pronunciación en una situación de inmersión y en qué medida estas creencias se ven reflejadas en su actuación en el aula. Tras hacer una revisión bibliográfica del estado de la cuestión llevaré a cabo una investigación en dos etapas: una primera fase de grabación de clases en audio para analizar el tratamiento de la pronunciación en el aula y una segunda fase de análisis de las creencias de los profesores que puedan fundamentar su actuación. Para mí lo fundamental será disponer de un buen punto de partida para ser capaz de formular un plan de acción formativa para los profesores de mi centro y para incorporar mejoras a nuestros cursos de formación de profesores. Pero esto será objeto de una investigación posterior.

Coverage effects on the magnetism of Fe/MgO(001) ultrathin films

Different aspects of the structure-magnetism and morphology-magnetism correlation in the ultrathin limit are studied in epitaxial Fe films grown on MgO(001). In the initial stages of growth the presence of substrate steps, intrinsically higher than an Fe atomic layer, prevent the connection between Fe islands and hence the formation of large volume magnetic regions. This is proposed as an explanation to the superparamagnetic nature of ultrathin Fe films grown on MgO in addition to the usually considered islanded, or Vollmer-Weber, growth. Using this model, we explain the observed transition from superparamagnetism to ferromagnetism for Fe coverages above 3 monolayers (ML). However, even though ferromagnetism and magnetocrystalline anisotropy are observed for 4 ML, complete coverage of the MgO substrate by the Fe ultrathin films only occurs around 6 ML as determined by polar Kerr spectra and simulations that consider different coverage situations. In annealed 3.5 ML Fe films, shape or configurational anisotropy dominates the intrinsic magnetocrystalline anisotropy, due to an annealing induced continuous to islanded morphological transition. A small interface anisotropy in thicker films is observed, probably due to dislocations observed at the Fe¿MgO(001) interface.

Size effects in the magneto-optical response of Co nanoparticles

A study of the magneto-optical (MO) spectral response of Co nanoparticles embedded in MgO as a function of their size and concentration in the spectral range from 1.4 to 4.3 eV is presented. The nanoparticle layers were obtained by sputtering at different deposition temperatures. Transmission electron microscopy measurements show that the nanoparticles have a complex structure which consists of a crystalline core having a hexagonal close-packed structure and an amorphous crust. Using an effective-medium approximation we have obtained the MO constants of the Co nanoparticles. These MO constants are different from those of continuous Co layers and depend on the size of the crystalline core. We associate these changes with the size effect of the intraband contribution to the MO constants, related to a reduction of the relaxation time of the electrons into the nanoparticles.