Strain profiles in thin films: influence of a coherently diffracting substrate and thickness fluctuations

Alexandre Boulle (1) , F. Conchon (2, 3) , R. Guinebretière (1)

1 IRCER-AXE3 - IRCER - Axe 3 : organisation structurale multiéchelle des matériaux
2 PPrime [Poitiers] - Institut Pprime [UPR 3346]
3 SPCTS - Science des Procédés Céramiques et de Traitements de Surface

A simple least-square fitting-based method is described for the determination of strain profiles in epitaxial films using high-resolution X-ray diffraction. The method is model-independent, i.e. it does not require any "guess" model for the shape of the strain profile. The shape of the vertical displacement profile is modeled using the versatile cubic B-spline functions, which puts smoothness and curvature constraints on the fitting procedure. The effect of a coherently diffracting substrate is taken into account as well as the effects of film thickness fluctuations. The model is applied to the determination of strain profiles in SmNiO 3 films epitaxially grown on (001) SrTiO 3 substrates. The shape of the retrieved strain profile is discussed in terms of oxygen vacancies.

Mots clés: high-resolution X-ray diffraction; strain profiles; thin films; high-resolution X-ray diffraction.

Domaines: Matériaux

Alexandre Boulle, F. Conchon, R. Guinebretière. Strain profiles in thin films: influence of a coherently diffracting substrate and thickness fluctuations. Journal of Applied Crystallography, 2009, 42 (1), pp.85-92. ⟨10.1107/S0021889808036406⟩. ⟨hal-02193848⟩