Highly oriented multiferroic Ba2NdFeNb4O15 -based composite thin films with tetragonal tungsten bronze structure on silicon substrates

Thameur Hajlaoui (1) , Catalin Harnagea (1) , Dominique Michau (2) , Michaël Josse (2) , Alain Pignolet (1)

1 INRS - Institut National de la Recherche Scientifique [Québec]
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Multiferroic Ba2NdFeNb4O15-based composite thin films have been deposited on Pt/Si(100) substrates by pulsed laser deposition. Structural investigation demonstrated the achievement of highly c-oriented thin films of Ba2NdFeNb4O15 upon optimization. Macroscopic ferroelectric hysteresis loops showed that ferroelectric properties were considerably improved compared to those of the ceramic of the same composition. This improvement was related to the degree of c-orientation of the films, which was controlled via the growth conditions. The investigation of the films microelectromechanical properties confirmed that ferroelectricity was conserved down to the nanoscale. Furthermore, after an initial modest decrease of the polarization of less than 4% during the first 106 switching cycles, the films did not show any significant further fatigue up to 108 cycles. The presence of a magnetic secondary phase has been confirmed by measuring ferromagnetic hysteresis loops, demonstrating the achievement of ferroelectric-magnetic nanocomposite thin films based on tetragonal tungsten bronze Ba2NdFeNb4O15, which exhibit multiferroic properties at room temperature.

Mots clés: Multiferroic; Thin film; Composite; Room temperature properties

Domaines: Matériaux

Thameur Hajlaoui, Catalin Harnagea, Dominique Michau, Michaël Josse, Alain Pignolet. Highly oriented multiferroic Ba2NdFeNb4O15 -based composite thin films with tetragonal tungsten bronze structure on silicon substrates. Journal of Alloys and Compounds, 2017, 711, pp.480-487. ⟨10.1016/j.jallcom.2017.04.051⟩. ⟨hal-01529392⟩