Epitaxial LaMnO₃ films with remarkably fast oxygen transport properties at low temperature

Abstract

Unexpectedly high oxygen diffusion coefficients were measured for LaMnO3 at 500 °C, below its phase transition temperature, and in the range of interest for its potential use in micro Solid Oxide Fuel Cells (μ-SOFCs).

Metal‐Organic Chemical Vapor Deposition of Oxide Perovskite Films: A Facile Route to Complex Functional Systems

“…Lanthanum manganites or cobaltites, such as LaMnO 3 , [48] La 1-x Sr x MnO 3 (LSMO), [49] and LaCoO 3 , [50] well-known perovskite oxides with excellent electric and ionic conductivity, have also been grown by MOCVD. In particular, alkaline-earth doped rare-earth manganites (RE 1-x A x MnO 3 ; RE: La, Pr; A: Ca, Sr) [49,51] are famous for their exceptional magnetic and magnetoresistive characteristics.…”

“…Rodriguez-Lamas et al [48] have looked at the ionic mass transport characteristics of LaMnO 3+δ (LMO) as a potential oxygen electrode for SOFCs at low temperatures (500-600 °C) on two different SrTiO 3 and LaAlO 3 substrates (see scheme in Figure 6e). Pulsed injection MOCVD (PI-MOCVD) was used to produce dense thin LMO films on SrTiO 3 and LaAlO 3 single crystals using a precursor solution of La(thd) 3 and Mn(thd) 3 in m-xylene as solvent.…”

“…At 500 °C, the epitaxial LMO on LaAlO 3 showed particularly high oxygen diffusion coefficients. [48] Because of its strong mixed ionic and electronic conductivity, LaCoO 3 (LCO) might be utilized as a cathode in solid oxide fuel cells, or as a thick ceramic membrane to separate oxygen from air. Catalano et al [50] reported on a simple in situ MOCVD strategy that employed a molten precursor mixture consisting of La (hfa) 3 diglyme and Co(tta) 2 tmeda at relatively high temperatures to create good quality LCO films on single crystal LaAlO 3 (001) substrates.…”

“…However, integrating them into CMOScompatible substrates like silicon wafers is difficult. Rodriguez-Lamas et al [48,152] recently developed three different growth strategies to control the oxygen content (δ) and Mn oxidation state of the active LaMnO 3+δ material and to tune its transition from an orthorhombic to a rhombohedral phase. They deposited LMO films on commercial platinized silicon using PI-MOCVD approach, with a solution of La(thd) 3 and Mn(thd) 3 dissolved in m-xylene.…”

“…LMO film deposited on STO: e) scheme of the18 O exchange for an LMO film deposited on STO; f,g) LMO/STO and LMO/LAO X-ray diffraction patterns; h,i) planar SEM and AFM images of LMO deposited on STO and LAO, respectively. Adapted with permission [48]. Copyright 2021, Royal Society Chemistry.…”