One-Stage Hydrothermal Growth and Characterization of Epitaxial LaMnO3 Films on SrTiO3 Substrate

Abstract

Epitaxial LaMnO3 thin films were grown on SrTiO3 substrate using a one-stage hydrothermal route from La(NO3)3, MnCl2 and KMnO4 in an aqueous solution of 10 M KOH at 340 °C. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) indicate full coverage of LaMnO3 on the substrate. X-ray diffraction in the symmetric ω/2θ mode suggests the film has an out-of-plane preferred orientation along the [001] direction of the substrate. The LaMnO3 epitaxial thin film growth mechanism is proposed based on the analysis of the atomic sharp interface formed between LaMnO3 and the SrTiO3 substrate, as seen by aberration−corrected scanning transmission electron microscopy (AC−STEM) imaging in combination with electronic energy loss spectroscopy (EELS). Compared with the conventional vapor deposition methods, the one-stage hydrothermal route opens up a new way to fabricate complex oxide epitaxial heterostructures.

Hydrothermal Growth and Orientation of LaFeO3 Epitaxial Films

“…According to the work by Guo [ 27 ] and Ahn [ 30 ], as indicated by Figure 6 and Figure 8 , the growth mode and growth mechanism of LaFeO 3 epitaxial thin films grown on SrTiO 3 substrates by the one-step hydrothermal can be concluded. The growth mode is in accordance with island growth.…”

“…Huang et al [ 26 ] successfully fabricated a BiFeO 3 epitaxial film on a SrTiO 3 substrate via the one-step hydrothermal method, achieving the complete coverage of the substrate at 180 °C for 6 h. The quality of the epitaxial film improved with the increasing temperature and time, and the film exhibited certain dielectric and energy storage properties after annealing. Guo et al [ 27 ] successfully prepared a LaMnO 3 epitaxial film on a SrTiO 3 substrate using the one-step hydrothermal method. ADF-STEM cross-section analysis revealed particle exchange and stress strain at the junction of the epitaxial film, confirming expansion outside the lattice plane.…”

Structure and magnetic properties of epitaxial Sr-LaMnO3 thin films obtained by polymer assisted deposition

“…It is important to underline that with the increase in Sr-content bulk La 1 − x Sr x MnO 3 undergoes an orthorhombic-to-rhombohedral phase transition for x > 0.17 and the appearance of the rhombohedral (R-3c) LMO phase can be expected in the bulk La 0.7 Sr 0.3 MnO 3 sample [38,39]. The presence of orthorhombic and coexistence of orthorhombic and rhombohedral phases was also reported for Srdoped LMO lms [33,38].…”