In-situ x-ray scattering study of pulsed-laser deposition of LuFeO₃/Pt systems

V. Holý¹, L. Horák¹, S. Bauer², A. Rodriques², T. Baumbach², R. Schneider³, X. Jin³

¹Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic

²Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany

³Laboratory for Electron Microscopy, Karlsruhe Institute of Technology, Engesserstr. 7, D-76131 Karlsruhe, Germany

holy@mag.mff.cuni.cz

Growth of multiferroic epitaxial layers of hexagonal LuFeO₃ has been studied by x-ray scattering in-situ during pulsed-laser deposition (PLD). For this purpose we used a unique PLD chamber attached to the NANO-beamline of the Institute of Photon Science and Synchrotron Radiation (IPS) attached to the KARA storage ring (Karlsruhe, Germany). The LuFeO₃ layers have been deposited on single-crystalline sapphire substrates, in some samples we also deposited thin Pt interlayers prior to the LuFeO₃ growth. In the first part of the talk I report on grazing-incidence small-angle scattering (GISAXS) measured in-situ during the Pt deposition. From the data we determined the Pt growth kinetics, in particular we study the dependence on the island-to-layer percolation threshold on the substrate temperature [1]. In the second part I discuss the parameters of the LuFeO₃ thin layers and their development during deposition [2]. The layers are mosaic and we studied the angular mosaic spread and mean size of the mosaic blocks as functions of the substrate deposition temperature and of the Pt thickness underneath. The final part of the talk is devoted to the study of growth oscillations during the LuFeO3 deposition; the oscillations were recorded by measuring the time dependence of the intensity of the quasi-forbidden reflex (0003) of LuFeO₃. From the data we determined the growth rate and the height of the Ehrlich-Schwöbel diffusion barrier as functions of the laser repetition frequency [3].

[1] V. Holý, S. Bauer, A. Rodrigues, L. Horák, X. Jin, R. Schneider, T. Baumbach, Phys. Rev. B 102 (2020) 125435.

[2] S. Bauer, A. Rodrigues, L. Horák, X.W. Jin, R Schneider, T. Baumbach, V. Holý, Materials 13 (2020) 61.

[3[ V. Holý, S. Bauer, A. Rodrigues, B. Nergis, L. Horák, R. Schneider, X. Jin, T. Baumbach, Applied Surf. Science, submitted.

The work was supported by the Czech Science Foundation (project No. 19-10799J) and by the project NanoCent financed by European Regional Development Fund (ERDF, project No. CZ.02.1.01/0.0/0.0/15.003/0000485). The additional funding by the German Research Foundation within the framework of the projects SCHN 669/11 and BA 1642/8-1 is gratefully acknowledged.