| Autor: |
Reisner G. M., Patlagan L., Genossar J., Fisher B. |
| Jazyk: |
angličtina |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
EPJ Web of Conferences, Vol 40, p 15009 (2013) |
| Druh dokumentu: |
article |
| ISSN: |
2100-014X |
| DOI: |
10.1051/epjconf/20134015009 |
| Popis: |
Striking non-linear conductivity effects induced by surprisingly low electric-fields in charge-ordered oxides, were reported variously as dielectric breakdown, charge-order collapse, depinning of charge-density-waves or other electronic effects. Our pulsed and d.c. I-V measurements on resistive oxides show that non-linear conductivity of electronic origin at low electric-fields is a rare phenomenon. In the majority of cases we detected no deviations from linearity in pulsed I-V characteristics under fields up to E ~ 500 V/cm. Current-controlled negative-differential-resistance (NDR) and hysteresis were found in d.c. measurements at fields that decrease with increasing temperatures, a behavior typical of Joule heating in materials with negative temperature coefficient of resistivity. For the d.c. I-V characteristics of our samples exhibiting NDR, we found a rather unexpected correlation between ρ(Em) - the resistivity at maximum field (at the onset of NDR) and ρ(E=0) – the ohmic resistivity. The data points for ρ(Em) versus ρ(E=0) obtained from such characteristics of 13 samples (8 manganites, 4 nickelates and one multiferroic) at various ambient temperatures, plotted together on a log-log scale, follow closely a linear dependence with slope one that spans more than five orders of magnitude. This dependence is reproduced by several simple models. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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