GASTON GARBARINO - Multiple polyamorphisms and superconductivity in Ce-based metallic glasses

Gaston Garbarino.

European Synchrotron Radiation Facility.

Jueves 4/12/2014, 14 hs.

Aula Seminario, 2do piso, Pabellón I.

Metallic glasses are in the cutting edge of research in materials science for both their unique properties that yield a variety of commercial applications like micro-electromechanical systems, pressure sensors or biocompatible prosthesis and for fundamental studies on the nature of the glass transition and other related phenomena. In this presentation we will present coupled high pressure diffraction, inelastic X ray scattering and resistivity measurements on the Ce₇₀Al₁₀Ni₁₀Cu₁₀ alloy. In this system a series of pressure induced polyamorphic transformations have been observed and the differences in the transport properties of the different amorphous phases are discussed and correlated to their microstructure. Especially we will concentrate in the low temperature behaviour of the transport properties where we observe a minimum of the resistivity associated with the Kondo effect. Application of hydrostatic pressure induces a reduction of the temperature where this minimum is observed, the disappearance of the Kondo behaviour and the appearance of superconductivity. We will discuss and analyze the correlation of the polyamorphic transitions with the anomalies in the transport properties.