Growth of CaFeO_x/LaFeO_3 Superlattice on SrTiO_3(100) Substrates

摘要

The CaFeO_x(CFO) and LaFeO_3(LFO) thin films as well as superlattices were fabricated on SrTiO_3(100) substrates by pulsed laser deposition (PLD) method. The tetragonal LFO film grew with layer-by-layer growth mode until approximately 40 layers. In the case of CFO, initial three layers showed layer-by-layer growth, and afterward the growth mode was transferred to two layers-by-two layers (TLTL) growth mode. The RHEED oscillation was observed until the end of the growth, approximately 50nm. Orthorhombic twin CaFeO_(2.5) (CFO2.5) structure was obtained. However, it is expected that the initial three CFO layers are CaFeO_3 (CFO3) with the valence of Fe~(4+). The CFO and LFO superlattice showed a step-terraces surface, and the superlattice satellite peaks in a 2θ-θ and reciprocal space mapping (RSM) x-ray diffraction (XRD) measurements, indicating that the clear interfaces were fabricated.