Superlattices of $({\mathrm{LaMnO}}_{3}{)}_{2n}/({\mathrm{SrMnO}}_{3}{)}_{n}$ ($1\ensuremath{\le}n\ensuremath{\le}5$), composed of the gapped insulators ${\mathrm{LaMnO}}_{3}$ and ${\mathrm{SrMnO}}_{3}$, undergo a metal-insulator transition as a function of $n$, being metallic for $n\ensuremath{\le}2$ and insulating for $n\ensuremath{\ge}3$. Measurements of transport, magnetization, and polarized neutron reflectivity reveal that the ferromagnetism is relatively uniform in the metallic state, and is strongly modulated in the insulating state, being high in ${\mathrm{LaMnO}}_{3}$ and suppressed in ${\mathrm{SrMnO}}_{3}$. The modulation is consistent with a Mott transition driven by the proximity between the $({\mathrm{LaMnO}}_{3})/({\mathrm{SrMnO}}_{3})$ interfaces. The insulating state for $n\ensuremath{\ge}3$ obeys variable range hopping at low temperatures. We suggest that this is due to states at the Fermi level that emerge at the $({\mathrm{LaMnO}}_{3})/({\mathrm{SrMnO}}_{3})$ interfaces and are localized by disorder.

Metal-insulator transition and its relation to magnetic structure in (LaMnO3)2n/(SrMnO3)n superlattices.

Complex transition metal oxides have played a central role in the study of magnetic materials, serving as model systems for explorations of fundamental exchange interactions and the relationships between structural, electronic, and magnetic responses. Enabled by advances in epitaxial synthesis techniques, abrupt heterointerfaces and superlattices have emerged as a powerful platform for engineering novel magnetic behavior in oxides. Following a brief introduction to the dominant exchange mechanisms in metal oxides, we review the general means by which interfacial magnetism can be tailored in ABO3 perovskites, including interfacial charge transfer, epitaxial strain and structural coupling, orbital polarizations and reconstructions, and tailoring exchange interactions via cation ordering. Recent examples are provided to illustrate how these strategies have been employed at isolated interfaces and in short-period superlattices. We conclude by briefly discussing underexplored and emerging research directions i...

Magnetic Oxide Heterostructures

A magnetic tunnel junction consists of two ferromagnetic conducting electrodes separated by an insulating thin layer The performance of such a system strikingly depends on the last conducting atomic layers in contact with the insulator Consequently, the present paper reports a nanoscale electron energy loss spectroscopy (EELS) study, which has been performed across a couple of La066Sr033MnO3,/SrTiO3/La066Sr033MnO3 tunnel junctions with different barrier thickness es (15 nm and 5 nm respectively) It aims at determining not only the chemical composition in the interface areas, but also the effect of the neighbouring atoms on their electronic structure Using recent improvements in the STEM-EELS data acquisition and processing techniques (systematic use of spectrum-line and spectrum-image modes, multivariate statistical analysis, 2D energy deconvolution schemes, etc), the local chemical information is better extracted with shorter acquisition times, while the large increase of the data set contributes to validate the results Within the accuracy level of these measurements, the elemental composition of the different phases remains stable up to the interfaces with no evidence of extra doping Furthermore, weak changes on the Mn-2p edge fine structures (weak shift to lower energy loss values and extra splitting on the top of the Mn L3 line are observed on all the interfaces They are interpreted as a consequence of a slight reduction of the local Mn valence likely accompanied by a strain induced change in local symmetry The discussion is focussed on all spectral changes identified at a (sub)nanometer scale and their potential effects on the degradation of magnetic and transport properties measured, close to room temperature, at a macroscopic level

EELS study of interfaces in magnetoresistive LSMO/STO/LSMO tunnel junctions

The control of matter properties (transport, magnetic, dielectric,…) using synthesis as thin films is strongly hindered by the lack of reliable theories, able to guide the design of new systems, through the understanding of the interface effects and of the way the substrate constraints are imposed on the material. The present Letter analyzes the energetic contributions at the interfaces, and proposes a model describing the microscopic mechanisms governing the interactions at an epitaxial interface between a manganite and another transition metal oxide in perovskite structure (as for instance SrTiO3). The model is checked against experimental results and literature analysis.

https://hal.archives-ouvertes.fr/hal-00590619/document

Interface effects in perovskite thin films.

Effect of A-site substitution by Ca or Sr on the structure and electrochemical performance of LaMnO3 perovskite

Epitaxially grown heterostructures consisting of alternating layers of ${\mathrm{LaMnO}}_{3}$ (LMO, 9 or 15 unit cells) and ${\mathrm{SrMnO}}_{3}$ (SMO, 4 or 6 unit cells) on a ${\mathrm{SrTiO}}_{3}(100)$ (STO(100)) substrate have been studied by a combination of high resolution transmission electron microscopy (HRTEM), electron diffraction, quantitative electron energy loss spectroscopy (EELS) with model fitting, energy filtered TEM (EFTEM) and imaging spectroscopy on an atomic scale. The combination of these techniques is necessary for the structural, chemical, and electronic characterization of these heterostructures. A model is proposed containing chemically and structurally sharp interfaces. The ${\mathrm{SrMnO}}_{3}$ layers are stabilized in a $\mathrm{Pm}3m$ structure between two LMO layers. Tensile stress causes oxygen deficiency in the SMO layers increasing the number of $3d$ electrons on the Mn sites to resemble the ${\mathrm{Mn}}^{3+}$ sites in LMO. The energy loss near edge structure (ELNES) of O and Mn is compared for both LMO and SMO layers and shows that the Mn-O bonds have a partially covalent character. The absence of a strong valency effect in the Mn ELNES is due to the oxygen vacancies in SMO.

/pdf/srtio-3-100-lamno-3-m-srmno-3-n-layered-heterostructures-a-59rnwascr1.pdf

SrTiO 3 (100)/(LaMnO 3 ) m (SrMnO 3 ) n layered heterostructures: A combined EELS and TEM study

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

B. Mercey

Author Tools

Chat about Author

Papers

SrTiO 3 (100)/(LaMnO 3 ) m (SrMnO 3 ) n layered heterostructures: A combined EELS and TEM study