Science

#Epitaxial antiperovskite/perovskite heterostructures for materials design

#Epitaxial antiperovskite/perovskite heterostructures for materials design

Epitaxial antiperovskite/perovskite heterostructures for materials design
Epitaxial antiperovskite/perovskite heterostructures for materials design
XRD structural characterization of a 60-nm-thick Mn3GaN grown on a (001)-oriented LSAT substrate. (A) Wide-angle θ-2θ spectrum only shows the (00l) reflections of the LSAT substrate and the Mn3GaN film, demonstrating that the film is (001)-oriented and single phase. Inset shows registered reflection high-energy electron diffraction (RHEED) pattern of the specular diffraction spot after growth. (B) Short-range θ-2θ scan around the (002) diffraction peak of the Mn3GaN film showing Kiessig fringes, indicating pristine interfaces and high crystalline quality of the film. (C) Rocking curve of the (002) Mn3GaN peak. (D) Three hundred sixty–degree ϕ-scans around the Mn3GaN and LSAT (022) peaks demonstrate cube-on-cube epitaxial relationship. (E) Reciprocal space mapping (RSM) around the LSAT (-113) reciprocal lattice point shows that the Mn3GaN is strain relaxed. a.u., arbitrary units. Credit: Science Advances, doi: 10.1126/sciadv.aba4017

To understand the structure and chemical composition of the Mn3GaN/LSAT interface, Quintela et al. combined atomic-resolution scanning transmission electron microscopy (STEM) with electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDS). The first interfacial Mn3GaN monolayer showed a pattern of alternating bright and dark spots to indicate compositional or structural reconfiguration at the interface. Using simulations and structural chemical analyses, the team showed transitions from the LSAT substrate to the Mn3GaN film mediated through a sharp interfacial monolayer. To determine the atomic structure of this interfacial monolayer, Quintela et al. performed additional STEM and EDS studies and showed the ordering of atoms in a two-dimensional (2-D) periodic structure with rotational symmetry.
First-principles calculations
The team performed first-principles calculations to study the stability of the interfacial model derived from atomic resolution experiments. Using simulations, they calculated the formation energies to test for stability and confirmed the interfacial model to be energetically stable. Additional work, however, showed apparent discrepancies between the experimental and theoretical studies, which the scientists credited to the onset of Mn3GaN growth in the presence of an energy barrier, where the discrepancy prevented the system from relaxing from the local to the global energy minimum. Quintela et al. further explored this hypothesis in their work. The combined experimental and theoretical studies showed how the interfacial monolayer worked as a structural bridge between the perovskite substrate and antiperovskite film to establish heteroepitaxy between the nonisostructural (dissimilar crystal structure) materials with different chemical composition and binding.



More information:
Camilo X. Quintela et al. Epitaxial antiperovskite/perovskite heterostructures for materials design, Science Advances (2020). DOI: 10.1126/sciadv.aba4017

J. Mannhart et al. Oxide Interfaces—An Opportunity for Electronics, Science (2010). DOI: 10.1126/science.1181862
A. H. MacDonald et al. Antiferromagnetic metal spintronics, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (2011). DOI: 10.1098/rsta.2011.0014

© 2020 Science X Network

Citation:
Epitaxial antiperovskite/perovskite heterostructures for materials design (2020, July 30)
retrieved 30 July 2020
from https://phys.org/news/2020-07-epitaxial-antiperovskiteperovskite-heterostructures-materials.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

If you want to read more Like this articles, you can visit our Science category.

if you want to watch Movies or Tv Shows go to Dizi.BuradaBiliyorum.Com for forums sites go to Forum.BuradaBiliyorum.Com

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button
Close

Please allow ads on our site

Please consider supporting us by disabling your ad blocker!