Current localisation and redistribution as the basis of discontinuous current controlled negative differential resistance in NbOx
| Autor: | Nandi, Sanjoy Kumar, Nath, Shimul Kanti, Helou, Assaad El, Li, Shuai, Liu, Xinjun, Raad, Peter E., Elliman, Robert G. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Advanced Functional Materials (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1002/adfm.201906731 |
| Popis: | In-situ thermo-reflectance imaging is used to show that the discontinuous, snap-back mode of current-controlled negative differential resistance (CC-NDR) in NbOx-based devices is a direct consequence of current localization and redistribution. Current localisation is shown to result from the creation of a conductive filament either during electroforming or from current bifurcation due to the super-linear temperature dependence of the film conductivity. The snap-back response then arises from current redistribution between regions of low and high current-density due to the rapid increase in conductivity created within the high current density region. This redistribution is further shown to depend on the relative resistance of the low current-density region with the characteristics of NbOx cross-point devices transitioning between continuous and discontinuous snap-back modes at critical values of film conductivity, area, thickness and temperature, as predicted. These results clearly demonstrate that snap-back is a generic response that arises from current localization and redistribution within the oxide film rather than a material-specific phase transition, thus resolving a long-standing controversy. Comment: 21 Pages |
| Databáze: | arXiv |
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