Nanoscale Probing of Elastic–Electronic Response to Vacancy Motion in NiO Nanocrystals

Journal Article · Tue Jul 25 00:00:00 EDT 2017 · ACS Nano

DOI:https://doi.org/10.1021/acsnano.7b03826· OSTI ID:1414712

Kurnia, Fran ^[1]; Cheung, Jeffrey ^[1]; Cheng, Xuan ^[1]; Sullaphen, Jivika ^[1]; Kalinin, Sergei V.  ^[2]; Valanoor, Nagarajan  ^[1]; Vasudevan, Rama K.  ^[2]

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1. Univ. of New South Wales, Sydney, NSW (Australia). School of Materials Science and Engineering
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)

Measuring the diffusion of ions and vacancies at nanometer length scales is crucial to understanding fundamental mechanisms driving technologies as diverse as batteries, fuel cells, and memristors; yet such measurements remain extremely challenging. Here in this paper, we employ a multimodal scanning probe microscopy (SPM) technique to explore the interplay between electronic, elastic, and ionic processes via first-order reversal curve I–V measurements in conjunction with electrochemical strain microscopy (ESM). The technique is employed to investigate the diffusion of oxygen vacancies in model epitaxial nickel oxide (NiO) nanocrystals with resistive switching characteristics. Results indicate that opening of the ESM hysteresis loop is strongly correlated with changes to the resonant frequency, hinting that elastic changes stem from the motion of oxygen (or cation) vacancies in the probed volume of the SPM tip. These changes are further correlated to the current measured on each nanostructure, which shows a hysteresis loop opening at larger (~2.5 V) voltage windows, suggesting the threshold field for vacancy migration. This study highlights the utility of local multimodal SPM in determining functional and chemical changes in nanoscale volumes in nanostructured NiO, with potential use to explore a wide variety of materials including phase-change memories and memristive devices in combination with site-correlated chemical imaging tools.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1414712
• Journal Information: ACS Nano, Vol. 11, Issue 8; ISSN 1936-0851
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
epitaxial
first-order reversal curve
nanocrystals
nickel oxide
resistive switching
scanning probe microscopy