skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on September 3, 2020

Title: Growth of metallic delafossite PdCo O 2 by molecular beam epitaxy

Abstract

The Pd- and Pt-based ABO 2 delafossites are a novel class of layered, triangular oxides with two-dimensional electronic structure and a large conductivity that rivals the noble metals. In this work, we report successful growth of the metallic delafossite PdCoO 2 by molecular beam epitaxy (MBE). The key challenge is controlling the oxidation of Pd in the MBE environment where phase segregation is driven by the reduction of PdCoO 2 to cobalt oxide and metallic palladium. This is overcome by combining low-temperature (300 °C) atomic layer-by-layer MBE growth in the presence of reactive atomic oxygen with a postgrowth high-temperature anneal. Thickness dependence (5–265 nm) reveals that in the thin regime (<75 nm), the resistivity scales inversely with thickness, likely dominated by surface scattering; for thicker films, the resistivity approaches the values reported for the best bulk crystals at room temperature, but the low-temperature resistivity is limited by structural twins. Our report shows that the combination of MBE growth and a postgrowth anneal provides a route to creating high-quality films in this interesting family of layered, triangular oxides.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Rutgers Univ., Piscataway, NJ (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE
OSTI Identifier:
1561648
Alternate Identifier(s):
OSTI ID: 1560305
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 3; Journal Issue: 9; Journal ID: ISSN 2475-9953
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Delafossite; PdCoO2; Triangular oxides; Thin films; Epitaxy

Citation Formats

Brahlek, Matthew, Rimal, Gaurab, Ok, Jong Mok, Mukherjee, Debangshu, Mazza, Alessandro R., Lu, Qiyang, Lee, Ho Nyung, Ward, T. Zac, Unocic, Raymond R., Eres, Gyula, and Oh, Seongshik. Growth of metallic delafossite PdCoO2 by molecular beam epitaxy. United States: N. p., 2019. Web. doi:10.1103/PhysRevMaterials.3.093401.
Brahlek, Matthew, Rimal, Gaurab, Ok, Jong Mok, Mukherjee, Debangshu, Mazza, Alessandro R., Lu, Qiyang, Lee, Ho Nyung, Ward, T. Zac, Unocic, Raymond R., Eres, Gyula, & Oh, Seongshik. Growth of metallic delafossite PdCoO2 by molecular beam epitaxy. United States. doi:10.1103/PhysRevMaterials.3.093401.
Brahlek, Matthew, Rimal, Gaurab, Ok, Jong Mok, Mukherjee, Debangshu, Mazza, Alessandro R., Lu, Qiyang, Lee, Ho Nyung, Ward, T. Zac, Unocic, Raymond R., Eres, Gyula, and Oh, Seongshik. Tue . "Growth of metallic delafossite PdCoO2 by molecular beam epitaxy". United States. doi:10.1103/PhysRevMaterials.3.093401.
@article{osti_1561648,
title = {Growth of metallic delafossite PdCoO2 by molecular beam epitaxy},
author = {Brahlek, Matthew and Rimal, Gaurab and Ok, Jong Mok and Mukherjee, Debangshu and Mazza, Alessandro R. and Lu, Qiyang and Lee, Ho Nyung and Ward, T. Zac and Unocic, Raymond R. and Eres, Gyula and Oh, Seongshik},
abstractNote = {The Pd- and Pt-based ABO2 delafossites are a novel class of layered, triangular oxides with two-dimensional electronic structure and a large conductivity that rivals the noble metals. In this work, we report successful growth of the metallic delafossite PdCoO2 by molecular beam epitaxy (MBE). The key challenge is controlling the oxidation of Pd in the MBE environment where phase segregation is driven by the reduction of PdCoO2 to cobalt oxide and metallic palladium. This is overcome by combining low-temperature (300 °C) atomic layer-by-layer MBE growth in the presence of reactive atomic oxygen with a postgrowth high-temperature anneal. Thickness dependence (5–265 nm) reveals that in the thin regime (<75 nm), the resistivity scales inversely with thickness, likely dominated by surface scattering; for thicker films, the resistivity approaches the values reported for the best bulk crystals at room temperature, but the low-temperature resistivity is limited by structural twins. Our report shows that the combination of MBE growth and a postgrowth anneal provides a route to creating high-quality films in this interesting family of layered, triangular oxides.},
doi = {10.1103/PhysRevMaterials.3.093401},
journal = {Physical Review Materials},
number = 9,
volume = 3,
place = {United States},
year = {2019},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 3, 2020
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Transparent Conducting Oxides—An Up-To-Date Overview
journal, April 2012