Orientation control of KNbO3 film grown on glass substrates by Ca2Nb3O10− nanosheets seed layer

F. Baudouin (1) , Valérie Demange (1, 2) , Sophie Ollivier (1) , L. Rault (2) , A.S. Brito (3) , A.S. Maia (3) , F. Gouttefangeas (2) , V. Bouquet (1) , S. Députier (1) , B. Berini (4) , A. Fouchet (5) , M. Guilloux-Viry (1, 2)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 ScanMAT - Synthèse Caractérisation Analyse de la Matière
3 UFPB - Universidade Federal da Paraiba / Federal University of Paraiba
4 GEMAC - Groupe d'Etude de la Matière Condensée
5 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

KNbO3 films have been deposited by pulsed laser deposition on glass substrates covered by Ca2Nb3O10− nanosheets used as seed layer, for the purpose of promoting (001) preferential orientation. Nanosheets have been prepared by the exfoliation process of HCa2Nb3O10 phase that is obtained by cation exchange of the Dion-Jacobson KCa2Nb3O10 phase in an acidic solution. Electron diffraction in transmission electron microscopy performed on KCa2Nb3O10 and HCa2Nb3O10 powders, and on Ca2Nb3O10− nanosheets revealed formation of local superstructures that are not detected by X-ray diffraction due to the weakness of superstructure reflection intensities. Nanosheets were deposited on substrates using the Langmuir-Blodgett method. A smooth covering of the surface was shown by atomic force microscopy. 200 nm thick KNbO3 films have been grown by pulsed laser deposition on Ca2Nb3O10−-NS/glass and on (001)SrTiO3 substrates for comparison. Substrates covered with nanosheets induced highly textured (001)-oriented thin film, which possesses a similar microstructure as epitaxial film on single crystalline strontium titanate substrate.

Mots clés: Inorganic nanosheets; Thin films; Langmuir - Blodgett; Pulsed laser deposition; Transmission electron microscopy

Domaines: Chimie; Matériaux

F. Baudouin, Valérie Demange, Sophie Ollivier, L. Rault, A.S. Brito, et al.. Orientation control of KNbO3 film grown on glass substrates by Ca2Nb3O10− nanosheets seed layer. Thin Solid Films, 2020, 693, pp.137682. ⟨10.1016/j.tsf.2019.137682⟩. ⟨hal-02378445⟩