Role of Interface Structure and Chemistry in Resistive Switching of NiO Nanocrystals on SrTiO3

Cheng, Xuan; Sullaphen, Jivika; Weyland, Matthew; Liu, Hongwei; Valanoor, Nagarajan

doi:10.1017/s1431927615004705

Cited by 2 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17 Moreover, detailed transmission electron microscopy (TEM) and electron energy loss spectrum (EELS) studies have revealed that the oxygen vacancies are preferably located at the NiO/Nb:STO interface and might be modulated by the electric field. 32 Therefore, it should be expected that the oxygen vacancies at the edge of the nanocrystals can actively drive the switching performance.…”

mentioning

confidence: 99%

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

et al. 2017

Self Cite

View full text Add to dashboard Cite

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, 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.

show abstract

mentioning

confidence: 99%

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

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…45,46 In the case of NiO grown on STO substrate, we know previously that the surface of STO is reduced. 47 Through careful and highresolution electron energy loss spectra (EELS) analysis, we found that the interface has Ti with lower valence (+4−δ) than the stoichiometric value of +4, even for STO several layers away from the Ni−STO interface. Thus, during growth the NiO/STO interface is not fully chemically stoichiometric.…”

Section: Acs Applied Electronic Materialsmentioning

confidence: 93%

“…Thus, during growth the NiO/STO interface is not fully chemically stoichiometric. 47 According to the metal/metal oxide interface encapsulation/ decoration theory, it has been proposed that minimization of surface energy is one of the driving forces for encapsulation. 42 To have encapsulation, two conditions are necessary: (1) the surface energy of the nanoparticle is larger than that of the substrate, and (2) the work function of the nanoparticle is higher than that of the substrate.…”

Section: Acs Applied Electronic Materialsmentioning

confidence: 99%

Encapsulation of Metal Oxide Nanoparticles by Oxide Supports during Epitaxial Growth

Cheng

Cheang-Wong

Weyland

et al. 2019

ACS Appl. Electron. Mater.

Self Cite

View full text Add to dashboard Cite

The traditional view of complex oxide heteroepitaxy is that the substrate is merely a passive bystander. Here we show that this is not always the case, in particular for a metal oxide/metal oxide interface during the synthesis of epitaxial nickel oxide (NiO) nanoislands on (001) strontium titanate (SrTiO 3 −STO) single crystal substrates. We find that the substrate atoms are driven to encapsulate the metal oxide nanocrystal islandsa phenomenon more commonly reported for metal/metal oxide heterogeneous catalysis where the migration of atoms from the support onto the functional nanoparticle system is driven by strong metal− support interactions (SMSI). High-resolution transmission electron microscopy (HRTEM), high angle angular dark field (HAADF) scanning transmission electron microscopy (STEM), and electron tomography (ET) are used to reveal a clear physical displacement of the interface; the atoms from the STO substrate climb and cover the bottom facets of NiO nanoparticles during the synthesis process during which a unique caldera-shaped structure is formed. It is postulated that this phenomenon occurs to lower the work function and surface energy of the system. These results indicate that the SMSI could be important in the metal oxide/metal oxide systems. In this way changes to the substrate−film interface could be exploited by controlling and modifying the properties of nanoscaled functional oxides.

show abstract

Role of Interface Structure and Chemistry in Resistive Switching of NiO Nanocrystals on SrTiO3

Cited by 2 publications

References 1 publication

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

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

Encapsulation of Metal Oxide Nanoparticles by Oxide Supports during Epitaxial Growth

Contact Info

Product

Resources

About