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ABSTRACT: We deposited NiO films by using reactive dc sputtering on Pt/Ti/SiO2/Si substrates. Before depositing top Pt electrodes, conducting filaments are preformed using conductive atomic force microscope. Pt/NiO/Pt capacitor structures with controlled number of conducting filaments show unipolar resistive switching behaviors strongly dependent on the number of conducting filaments. Especially, set switching voltage distribution increases with the number of conducting filament.
Applied Physics Letters 05/2011; 98(19):192104-192104-3. · 3.84 Impact Factor
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ABSTRACT: We have compared resistance switching of NiO films deposited on Pt and SrRuO3 (SRO): unipolar switching in Pt/NiO/Pt and bipolar switching in Pt/NiO/SRO. Linear fitted current-voltage curves and capacitance-voltage results show that on- and off-states conductions in unipolar switching are dominated by inductive Ohmic behavior and Poole–Frenkel effect, respectively. However, the conductions of on- and off-states in bipolar switching follow capacitive Ohmic behavior and Schottky effect, respectively. Therefore, we infer that the mechanisms of the unipolar and bipolar switching behaviors in NiO films are related with changes in bulk-limited filamentary conduction and interfacial Schottky barrier, respectively.
Applied Physics Letters 07/2009; 95(2):022109-022109-3. · 3.84 Impact Factor
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M.-J. Lee,
S. Seo,
D.-C. Kim,
S.-E. Ahn,
D. H. Seo,
I.-K. Yoo,
I.-G. Baek,
D.-S. Kim,
I.-S. Byun,
S.-H. Kim,
I.-R. Hwang, J.-S. Kim,
S.-H. Jeon,
B. H. Park
Advanced Materials 12/2006; 19(1):73 - 76. · 13.88 Impact Factor
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S. Seo,
M. J. Lee,
D. C. Kim,
S. E. Ahn,
B.-H Park,
Y. S. Kim,
I. K. Yoo,
I. S. Byun,
I. R. Hwang,
S. H. Kim, J.-S. Kim,
J. S. Choi,
J. H. Lee,
S. H. Jeon,
S. H. Hong
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ABSTRACT: We investigated resistance switching in top-electrode/ Ni O / Pt structures where the top electrode was Au, Pt, Ti, or Al. For Pt / Ni O / Pt and Au / Ni O / Pt structures with ohmic contacts, the effective electric field inside the film was high enough to induce trapping or detrapping at defect states and thus resistance switching. For a Ti / Ni O / Pt structure with well-defined Schottky contact at Ti / Ni O interface accompanied by an appreciable voltage drop, the effective electric field inside the NiO film was not enough to induce resistance switching. For an Al / Ni O / Pt structure with a low Schottky barrier at the Al / Ni O interface, resistance switching could be induced at a higher voltage since the voltage drop at the Al / Ni O interface was not negligible but small.
Applied Physics Letters 01/2006; · 3.84 Impact Factor
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S. Seo,
M. J. Lee,
D. H. Seo,
E. J. Jeoung,
D.-S. Suh,
Y. S. Joung,
I. K. Yoo,
I. R. Hwang,
S. H. Kim,
I. S. Byun, J.-S. Kim,
J. S. Choi,
B. H. Park
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ABSTRACT: Negative resistance behavior and reproducible resistance switching were found in polycrystalline NiO films deposited by dc magnetron reactive sputtering methods. Oxygen to argon gas ratio during deposition was critical in deciding the detailed switching characteristics of either bi-stable memory switching or mono-stable threshold switching. Both metallic nickel defects and nickel vacancies influenced the negative resistance and the switching characteristics. We obtained a distribution of low resistance values which were dependent on the compliance current of high-to-low resistance switching. At 200 °C, the low-resistance state kept its initial resistance value while the high-resistance state reached 85% of its initial resistance value after 5×105 s. We suggested that the negative resistance and the switching mechanism could be described by electron conduction related to metallic nickel defect states existing in deep levels and by small-polaron hole hopping conduction.
Applied Physics Letters 12/2004; 85(23):5655-5657. · 3.84 Impact Factor
