Title: Local structure of potassium doped nickel oxide: A combined experimental-theoretical study

Abstract

The electronic structure of Mott and charge-transfer insulators can be tuned through charge doping to achieve a variety of fascinating physical properties, e.g., superconductivity, colossal magnetoresistance, and metal-to-insulator transitions. Strong correlations between d electrons give rise to these properties but they are also the reason why they are inherently difficult to model. This holds true especially for the evolution of properties upon charge doping. Here, we hole-dope nickel oxide with potassium and elucidate the resulting structure by using a range of experimental and theoretical tools; potassium is twice as big as nickel and is expected to lead to distortions in its vicinity. Our measurements of the x-ray absorption fine structure (XAFS) show a significant distortion around the dopant and that the dopant is fully incorporated in the nickel oxide matrix. In parallel, the theoretical investigations include developing a Gaussian process for quantum Monte Carlo calculations to determine the lowest energy local structure around the potassium dopant. While the optimal structures determined from density functional theory and quantum Monte Carlo calculations agree very well, we find a large discrepancy between the experimentally determined structures and the theoretical doped structures. Further modeling indicates that the discrepancy is likely due to vacancy defects.more » Furthermore, our work shows that potassium doping is a possible avenue to doping NiO, in spite of the size of the potassium dopant. In addition, the Gaussian process opens up a new route towards obtaining structure predictions outside of density functional theory.« less

Authors:

Wrobel, Friederike  ^[1];

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Shin, Hyeondeok ^[2]; Sterbinsky, George E. ^[3]; Hsiao, Haw -Wen ^[4]; Zuo, Jian -Min ^[4]; Ganesh, P. ^[5]; Krogel, Jaron T. ^[6]; Benali, Anouar ^[7]; Kent, Paul R. C. ^[8]; Heinonen, Olle  ^[9];

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Bhattacharya, Anand ^[1]

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+ Show Author Affiliations

1. Argonne National Lab. (ANL), Lemont, IL (United States). Materials Science Div.
2. Argonne National Lab. (ANL), Argonne, IL (United States). Computational Science Div.
3. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Div.
4. Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept. of Materials Science and Engineering
5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences
6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Div.
7. Argonne National Lab. (ANL), Argonne, IL (United States). Computational Science Div. and Leadership Computing Facility
8. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences and Computational Sciences and Engineering Div.
9. Argonne National Lab. (ANL), Lemont, IL (United States). Materials Science Div.; Northwestern Univ., Evanston, IL (United States). Center for Hierarchical Material Design, Northwestern-Argonne Inst. for Science and Engineering

Publication Date:

2019-11-18

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

OSTI Identifier:

1576988

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Materials

Additional Journal Information:

Journal Volume: 3; Journal Issue: 11; Journal ID: ISSN 2475-9953

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE