Growth of Ca2MnO4 Ruddlesden-Popper structured thin films using combinatorial substrate epitaxy

Abstract

The local epitaxial growth of pulsed laser deposited Ca 2 MnO 4 films on polycrystalline spark plasma sintered Sr 2 TiO 4 substrates was investigated to determine phase formation and preferred epitaxial orientation relationships (ORs) for isostructural Ruddlesden-Popper (RP) heteroepitaxy, further developing the high-throughput synthetic approach called Combinatorial Substrate Epitaxy (CSE). Both grazing incidence X-ray diffraction and electron backscatter diffraction patterns of the film and substrate were indexable as single-phase RP-structured compounds. The optimal growth temperature (between 650 C and 800 C) was found to be 750 C using the maximum value of the average image quality of the backscattered diffraction patterns. Films grew in a grain-over-grain pattern such that each Ca 2 MnO 4 grain had a single OR with the Sr 2 TiO 4 grain on which it grew. Three primary ORs described 47 out of 49 grain pairs that covered nearly all of RP orientation space. The first OR, found for 20 of the 49, was the expected RP unit-cell over RP unit-cell OR,

Combinatorial substrate epitaxy investigation of polytypic growth of AEMnO3 (AE = Ca, Sr)

“…Using CSE, we have analyzed the polytypic epitaxial growth of 3C and 4H perovskites on 3C and 4H substrates. As observed for other CSE experiments, [8][9][10][11][12][13][14][15] our films exhibited grain-over-grain epitaxy, allowing each individual grain to be treated as a single crystal, even for orientations with high Miller indices. All of the data shown above supports the hypothesis that the eutactic OR is the PEO for AEMnO 3 films on 4H SrMnO 3 and 3C SrTiO 3 polycrystalline substrates, over all of orientation space (ignoring the few outliers).…”

“…As a result, OIM had difficulty assigning the local phase and orientation in these grains. Compared to other CSE investigations for metastable film growth, the angular region of 3C epitaxial stabilization is narrower than reported for other metastable phases, but the preference for an individual orientation stabilizing metastable polymorphs is similar.…”

“…In CSE, polished polycrystalline substrates are used, which can be prepared in‐house for a wide range of structural families, and each grain of the substrate can be viewed as a single crystal with a unique orientation. Electron backscatter diffraction (EBSD) is used in CSE as a high‐throughput local structural probe to create phase and orientation maps across large areas of the substrate surface, as well as the deposited film . A single deposition of a film onto a polycrystalline substrate yields thousands of observations from which a broad understanding of phase stability and film‐substrate orientation relationships (ORs) can be developed.…”

“…Electron backscatter diffraction (EBSD) is used in CSE as a high-throughput local structural probe to create phase and orientation maps across large areas of the substrate surface, as well as the deposited film. [8][9][10][11][12][13][14][15] A single deposition of a film onto a polycrystalline substrate yields thousands of observations from which a broad understanding of phase stability and film-substrate orientation relationships (ORs) can be developed. For example, only a few ORs were found for epitaxial films on polycrystalline substrates across all of orientation space of the substrate.…”

Metastable monoclinic [110] layered perovskite Dy2Ti2O7 thin films for ferroelectric applications

“…In that case, each grain of the ceramic can be viewed as a single-substrate with a particular orientation, and one can screen the entire orientation space map in one single experiment. [4][5][6][7][8][9] It enables a highthroughput way to investigate the structure-property relationships as a function of orientation. 10,11 This approach can also be used to synthesize metastable phases.…”