Title: Abnormal in-plane epitaxy and formation mechanism of vertically aligned Au nanopillars in self-assembled CeO ₂ –Au metamaterial systems

Abstract

Metamaterials present great potential in the applications of solar cells and nanophotonics, such as super lenses and other meta devices, owing to their superior optical properties. In particular, hyperbolic metamaterials (HMMs) with exceptional optical anisotropy offer improved manipulation of light–matter interactions as well as a divergence in the density of states and thus show enhanced performances in related fields. Recently, the emerging field of oxide–metal vertically aligned nanocomposites (VANs) suggests a new approach to realize HMMs with flexible microstructural modulations. In this work, a new oxide–metal metamaterial system, CeO₂–Au, has been demonstrated with variable Au phase morphologies from nanoparticle-in-matrix (PIM), nanoantenna-in-matrix, to VAN. The effective morphology tuning through deposition background pressure, and the corresponding highly tunable optical performance of three distinctive morphologies, were systematically explored and analyzed. A hyperbolic dispersion at high wavelength has been confirmed in the nano-antenna CeO₂–Au thin film, proving this system as a promising candidate for HMM applications. More interestingly, a new and abnormal in-plane epitaxy of Au nanopillars following the large mismatched CeO₂ matrix instead of the well-matched SrTiO₃ substrate, was discovered. Additionally, the tilting angle of Au nanopillars, α, has been found to be a quantitative measure of the balance between kinetics and thermodynamicsmore » during the depositions of VANs. All these findings provide valuable information in the understanding of the VAN formation mechanisms and related morphology tuning.« less

Authors:

Lu, Juanjuan  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-4885-8287"

Zhang, Di  ^[2];

• Search DOE PAGES for author "Zhang, Di"
• Search DOE PAGES for ORCID "0000-0002-9199-5634"

Paldi, Robynne L. ^[1]; He, Zihao ^[3]; Lu, Ping ^[4]; Deitz, Julia ^[4]; Ahmad, Ahmad ^[1]; Dou, Hongyi ^[1]; Wang, Xuejing ^[1]; Liu, Juncheng  ^[1];

• Search DOE PAGES for author "Liu, Juncheng"
• Search DOE PAGES for ORCID "0000-0002-5895-0581"

Hu, Zedong ^[1]; Yang, Bo ^[1]; Zhang, Xinghang  ^[1];

• Search DOE PAGES for author "Zhang, Xinghang"
• Search DOE PAGES for ORCID "0000-0002-8380-8667"

El-Azab, Anter A. ^[1]; Wang, Haiyan  ^[5]

• Search DOE PAGES for author "Wang, Haiyan"
• Search DOE PAGES for ORCID "0000-0002-7397-1209"

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+ Show Author Affiliations

1. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA
2. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA, Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, NM 87545, USA
3. School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
4. Sandia National Laboratories, Albuquerque, NM 87185, USA
5. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA

Publication Date:

Mon Jul 31 00:00:00 EDT 2023

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1974810

Alternate Identifier(s):

OSTI ID: 1983866

Report Number(s):

LA-UR-23-25635
Journal ID: ISSN 2051-6347; MHAOAL

Grant/Contract Number:  

SC0020077; 89233218CNA000001; DMR-1809520; ECCS-1902644; AC02-05CH11231; NA0003525

Resource Type:

Published Article

Journal Name:

Materials Horizons

Additional Journal Information:

Journal Name: Materials Horizons Journal Volume: 10 Journal Issue: 8; Journal ID: ISSN 2051-6347

Publisher:

Royal Society of Chemistry (RSC)

Country of Publication:

United Kingdom

Language:

English

Subject:

36 MATERIALS SCIENCE