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Forming-free bipolar resistive switching in nonstoichiometric ceria films.

Ismail M, Huang CY, Panda D, Hung CJ, Tsai TL, Jieng JH, Lin CA, Chand U, Rana AM, Ahmed E, Talib I, Nadeem MY, Tseng TY - Nanoscale Res Lett (2014)

Bottom Line: X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions.In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism.The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan. tseng@cc.nctu.edu.tw.

ABSTRACT
The mechanism of forming-free bipolar resistive switching in a Zr/CeOx/Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrOy layer at the Zr/CeOx interface. X-ray diffraction studies of CeOx films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeOx film and in the nonstoichiometric ZrOy interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).

No MeSH data available.


Related in: MedlinePlus

XRD pattern of the CeOxfilm and cross-sectional TEM and EDX images of the Zr/CeOx/Pt device. (a) XRD pattern of the CeOx film deposited on Si wafer at room temperature. (b) Cross-sectional TEM image of the Zr/CeOx/Pt device. (c) EDX image of the Zr/CeOx/Pt device.
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Figure 1: XRD pattern of the CeOxfilm and cross-sectional TEM and EDX images of the Zr/CeOx/Pt device. (a) XRD pattern of the CeOx film deposited on Si wafer at room temperature. (b) Cross-sectional TEM image of the Zr/CeOx/Pt device. (c) EDX image of the Zr/CeOx/Pt device.

Mentions: Figure 1a shows the grazing angle (3°) XRD spectra of the CeOx thin film deposited on Si (100) substrate. It indicates that the CeOx film possesses a polycrystalline structure having (111), (200), (220), and (311) peaks, corresponding to the fluorite cubic structure (JCPDS ref. 34–0394). From the XRD analysis, the broad and wide diffraction peaks demonstrate that the CeOx film exhibits poor crystallization. This could be due to the small thickness (approximately 14 nm) of the film. Figure 1b shows the cross-sectional HRTEM image of the Zr/CeOx/Pt device, which indicates that the ZrOy layer is formed between CeOx and Zr interfaces. Figure 1c depicts the EDX spectra of the CeOx film. The elemental composition of the Zr/CeOx/Pt was determined by energy dispersion. The results from the EDX analysis that showed the main component present in this structure were O (38.41%), Zr (34. 05%), and Ce (3.83%). An oxygen peak at about 0.52 keV and Zr peaks at about 22.5 and 15.60 keV can be observed in the spectra.


Forming-free bipolar resistive switching in nonstoichiometric ceria films.

Ismail M, Huang CY, Panda D, Hung CJ, Tsai TL, Jieng JH, Lin CA, Chand U, Rana AM, Ahmed E, Talib I, Nadeem MY, Tseng TY - Nanoscale Res Lett (2014)

XRD pattern of the CeOxfilm and cross-sectional TEM and EDX images of the Zr/CeOx/Pt device. (a) XRD pattern of the CeOx film deposited on Si wafer at room temperature. (b) Cross-sectional TEM image of the Zr/CeOx/Pt device. (c) EDX image of the Zr/CeOx/Pt device.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927661&req=5

Figure 1: XRD pattern of the CeOxfilm and cross-sectional TEM and EDX images of the Zr/CeOx/Pt device. (a) XRD pattern of the CeOx film deposited on Si wafer at room temperature. (b) Cross-sectional TEM image of the Zr/CeOx/Pt device. (c) EDX image of the Zr/CeOx/Pt device.
Mentions: Figure 1a shows the grazing angle (3°) XRD spectra of the CeOx thin film deposited on Si (100) substrate. It indicates that the CeOx film possesses a polycrystalline structure having (111), (200), (220), and (311) peaks, corresponding to the fluorite cubic structure (JCPDS ref. 34–0394). From the XRD analysis, the broad and wide diffraction peaks demonstrate that the CeOx film exhibits poor crystallization. This could be due to the small thickness (approximately 14 nm) of the film. Figure 1b shows the cross-sectional HRTEM image of the Zr/CeOx/Pt device, which indicates that the ZrOy layer is formed between CeOx and Zr interfaces. Figure 1c depicts the EDX spectra of the CeOx film. The elemental composition of the Zr/CeOx/Pt was determined by energy dispersion. The results from the EDX analysis that showed the main component present in this structure were O (38.41%), Zr (34. 05%), and Ce (3.83%). An oxygen peak at about 0.52 keV and Zr peaks at about 22.5 and 15.60 keV can be observed in the spectra.

Bottom Line: X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions.In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism.The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan. tseng@cc.nctu.edu.tw.

ABSTRACT
The mechanism of forming-free bipolar resistive switching in a Zr/CeOx/Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrOy layer at the Zr/CeOx interface. X-ray diffraction studies of CeOx films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeOx film and in the nonstoichiometric ZrOy interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).

No MeSH data available.


Related in: MedlinePlus