PhD Student on ID10 beamline in the Complex systems and Biomedical sciences group

Thesis Subject:  Dynamics and structure of amorphous phase change materials combining Fast differential scanning calorimetry and X-rays

General Framework: Phase change materials (PCMs) are chalcogenide glasses that are attracting considerable interest thanks to their promising applications as next generation electronic memories and communication devices. A major drawback for their extensive use is given by ongoing microscopic relaxation processes, proper of all glasses, which may alter the performances of the material during preparation and operation. Understanding the structural and dynamic changes induced by the ongoing relaxation processes during thermo-mechanical treatments in amorphous solids is therefore crucial for the design of novel systems with extended service life.

Description of the Thesis work: This project aims at combining the recently developed fast differential scanning calorimetry (FDSC) with X-ray Photon Correlation Spectroscopy (XPCS) and high energy X-ray Diffraction (XRD) to build up precise recipes to predict and control the stability of the different PCM glasses subjected to hydrostatic compression and cryogenic thermal cycling. This study will serve as reference to improve the material properties and to investigate the microscopic mechanism by which residual stresses induced by thermal and mechanical deformations influence the atomic motion, structure and thermodynamic state of PCMs.

The project will be in collaboration between ESRF (Marco Cammarata and Marco di Michiel) and the Institut Néel of the CNRS in Grenoble (Beatrice Ruta). Secondments with collaborators in different European countries will be also envisaged, providing extensive mobility opportunities.

This Thesis work is part of the project GATES, Grenoble ATtractiveness and ExcellenceS, funded by the French National Agency (ANR) and ESRF. The student will be part both of the MRS group of the Institut Néel and of the ID10 team at ESRF.

Further information may be obtained from Marco Cammarata (tel.: +33 (0)4 76 88 23 91, email: marco.cammarata@esrf.fr) or Beatrice Ruta (beatrice.ruta@neel.cnrs.fr).