Epitaxial multifunctionnal multiferroic oxynitride thin films

Stage M2
CEA Saclay, Site de l’Orme des merisiers (91) Essonne, France
January 10 2025
February 1 2025
5 month
2025-epitaxial-multifunctionnal-multiferroic-oxynitride-en

Domain, Specialties : Condensed matter physics
Keywords: Oxinitrides, molecular beam epitaxy, ferroélectricité, ferrimagnétisme, synchrotron, lithography

Research Unit : SPEC / LNO

Epitaxial multifunctionnal multiferroic oxynitride thin films

Summary

The objective of the internship is to grow epitaxial thin multiferroic ferrite/perovskite (CoFe2(OxN1-x)4/N:BaTiO3 oxynitride films by oxygen and nitrogen plasma assisted molecular beam epitaxy: a potentially new magnetoelectric material. We will proceed by nitrogen doping of oxide films for which the growth conditions are already mastered in the CEA/SPEC laboratory. The crystalline structure as well as the magnetic and ferroelectric properties will be studies.

Full description

Novel materials are required within the energy transition and modern communication technologies frameworks, in particular to produce clean energy and/or reduce electronic device consumption and overall materials usage. Within this context oxynitrides are a relevant class of materials. The magnetoelectric ones are very well suited to realize novel multifunctional sensors. Doping by charge carriers makes it possible to envisage new transport properties. The production of hybrid single crystalline thin oxynitride films is however challenging and has been little studied to date.

We will explore the possibility of modulating the properties of thin laminar oxide magnetoelectric films of N doped cobalt ferrite (CoFe2(OxN1-x)4, ferromagnetic) deposited on nitrogen doped barium titanate (N:BaTiO3, ferroelectric). Their growth conditions are already mastered and we will proceed by the addition of nitrogen plasma during growth. We will study the influence of the N doping on the electronic, magnetic and ferroelectric properties with respect to film thickness and growth conditions. Already existing magnetic dichroism data, for some situations, will be investigated in details.

Other researchers potentially involved:

  • Jean-Baptiste Moussy (SPEC/LNO)
  • Pâmella Vasconcelos (DES/ISAS/DRMP/S2CM/LM2T),
  • Sylvia Matzen (C2N)

Location

CEA Saclay, Site de l’Orme des merisiers (91) Essonne, France

Internship conditions

  • Internship duration: 5 months
  • Level of study: Bac+5
  • Training: Master 2
  • Continuation in PhD thesis: Yes
  • Application deadline: 10 janvier 2025

Experimental skills

Useful methods and technics:

The candidate will address the UHV techniques associated with the growth by molecular beam epitaxy. The techniques that will be used are Reflexion High Energy Electron Diffraction (RHEED), Auger Electron Spectroscopy (AES), Photoemission core level spectroscopy (XPS), Piezo Force Microscopy (PFM), magnetic measurements (VSM), lithography and ferroelectric measurements and X-ray diffraction. Electronic structure modeling will be used for the interpretation of spectroscopic data.

Langue : Anglais

Supervisor

Antoine BARBIER
Phone: 01.69.08.39.23
Email :

Head of the laboratory SPEC / LNO

Michel VIRET
Phone: 01.69.08.72.17