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Interest in layered Ruddlesden–Popper (RP) strongly correlated manganites of Pr0.5Ca1.5MnO4 as well as in their thin film polymorphs is motivated by the high temperature of charge orbital ordering above room temperature. The c‐axis orientation in epitaxial films is tailored by different SrTiO3 (STO) substrate orientations and CaMnO3 (CMO) buffer layers. Films on STO(110) show in‐plane alignment of the c‐axis parallel to the [100] direction. On STO(100), two possible directions of the in‐plane c‐axis lead to a mosaic like, quasi 2D nanostructure, consisting of RP, rock‐salt, and perovskite blocks. With the CMO buffer layer, Pr0.5Ca1.5MnO4 epitaxial films with c‐axis out‐of‐plane are realized. Different physical vapor deposition techniques as ion beam sputtering, pulsed laser deposition and metalorganic aerosol deposition are applied in order to distinguish effects of growth conditions from intrinsic epitaxial properties. Despite their very different growth conditions, surface morphology, crystal structure, and orientation of the thin films reveal a high level of similarity as verified by X‐ray diffraction, scanning, and high resolution transmission electron microscopy. For different epitaxial relations stress in the films is relaxed by means of modified interface chemistry. The charge ordering in the films occurs at a temperature close to that expected in bulk material. [ABSTRACT FROM AUTHOR]

Two series of B-site ordered, double-perovskite A2CoMnO6 and A2NiMnO6 (A = La, Pr, Nd, Sm, Gd) epitaxial films with thickness d ~ 100 nm were grown on SrTiO3(111) substrates via metalorganic aerosol deposition. Polarization and temperature-dependent Raman spectroscopy were carried out in order to determine the spin-phonon coupling constant, λ, and the impact of the A-site cation radius on the phonon properties. The reduction of the A-site cation radius from La3+ down to Gd3+ systematically shifts the Raman modes to lower wavenumbers, and decreases the magnetization-induced softening of the Ag breathing mode, described by the spin-phonon coupling constant, λ, which changes from λ = 1.42 cm−1 (La2CoMnO6) and λ = 1.53 cm−1 (La2NiMnO6) down to λ = 0.58 cm−1 (Gd2CoMnO6) and λ = 0.44 cm−1 (Gd2NiMnO6). A similar effect of the A-cation radius was established for the c-lattice parameter and Curie temperature, TC, in this series of double-perovskite films. Our observations directly demonstrate a strong impact of the lattice structure on the ferromagnetic superexchange interaction in double perovskites. Moreover, the A2CoMnO6 and A2NiMnO6 series exhibit very similar behavior of spin-phonon coupling due to the only moderate difference of Co2+ and Ni2+ cation size. [ABSTRACT FROM AUTHOR]

The preparation of cation-ordered thin films of correlated oxides is of great interest for both fundamental and applied research. The scientific long-term vision is strongly motivated by the perspective of studying electronic correlations in condensed matter without the presence of chemical or quenched disorder. A promising material platform provides double perovskite A2BB'O6 bulk samples with different types of B/B' ordering. However, the growth of A- and/or B-site-ordered correlated oxide thin films is known to be a challenging task. In this review, we evaluate the growth of double perovskite A2BB'O6 thin films by means of well-elaborated physical vacuum deposition techniques, such as pulsed laser deposition (PLD) and sputtering and compare them with a close-to-equilibrium growth with the metalorganic aerosol deposition (MAD) technique. The latter was further developed to grow an emergent interfacial double perovskite phase in LaNiO3/LaMnO3 superlattices, and finally, by way of a layer-by-layer route. The growth of La2CoMnO6 films on SrTiO3(111) substrates by sequential deposition of single perovskite layers of LaCoO3/LaMnO3/LaCoO3/... was demonstrated and the film properties were compared to those obtained within the state-of-the art growth mode. [ABSTRACT FROM AUTHOR]

Epitaxy, Ruddlesden-Popper manganites, thin film growth Ruddlesden-Popper Manganites: Tailoring c-Axis Orientation in Epitaxial Ruddlesden-Popper Pr0.5Ca1.5MnO4 Films (Adv. Keywords: epitaxy; Ruddlesden-Popper manganites; thin film growth EN epitaxy Ruddlesden-Popper manganites thin film growth 1 1 1 04/12/21 20210409 NES 210409 For Ruddlesden-Popper Pr SB 0.5 sb Ca SB 1.5 sb MnO SB 4 sb thin films grown on STO (100) the c-axis lies in-plane and two possible configurations are observed. [Extracted from the article]

We performed time-resolved nanoscale studies on the resistive switching of perovskite manganite thin films by means of conductive atomic force microscopy. Creep and recovery features have been observed in the evolution of metallic domains via pulse-train experiments and current map sequences. Local I(t) curves show 1/fα noise signatures during the switching process, a phenomenon which occurs in various physical processes consisting of discrete jumps of different sizes, such as the Barkhausen effect. Our results imply that the resistive switching falls into this universal class of effects with dynamics determined by the pinning and depinning of structural domain walls. [ABSTRACT FROM AUTHOR]