Nath, Rajib ; Raychaudhuri, A K ; Mukovskii, Ya M ; Mondal, Parthasarathi ; Bhattacharya, Dipten ; Mandal, P (2013) Electric field driven destabilization of the insulating state in nominally pure LaMnO3 Journal of Physics: Condensed Matter, 25 (15). p. 155605. ISSN 0953-8984
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Official URL: http://doi.org/10.1088/0953-8984/25/15/155605
Related URL: http://dx.doi.org/10.1088/0953-8984/25/15/155605
Abstract
We report an electric field driven destabilization of the insulating state in nominally pure LaMnO3 single crystal with a moderate field which leads to a resistive state transition below 300 K. The transition is between the insulating state in LaMnO3 and a high resistance bad metallic state that has a temperature independent resistivity. The transition occurs at a threshold field (Eth) that shows a steep enhancement on cooling. While at lower temperatures the transition is sharp and involves a large change in resistance, it softens on heating and is eventually absent above 280 K. When the Mn4+ content is increased by Sr substitution up to x = 0.1, the observed transition, although observable in a certain temperature range, softens considerably. This observation has been explained as a bias driven percolation type transition between two co-existing phases, where the majority phase is a charge and orbitally ordered polaronic insulating phase and the minority phase is a bad metallic phase. The mobile fraction f of the bad metallic phase deduced from the experimental data follows an activated kinetics as f = fo(E)exp(−Δ/kBT) with the activation energy Δ ≈ 200 meV, and the pre-factor fo(E) is a strong function of the field that leads to a rapid enhancement of f on application of field, leading to the resistive state transition. We suggest likely scenarios for such co-existing phases in nominally pure LaMnO3 that can lead to the bias driven percolation type transition.
Item Type: | Article |
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Source: | Copyright of this article belongs to Institute of Physics Publishing. |
ID Code: | 122832 |
Deposited On: | 17 Aug 2021 06:32 |
Last Modified: | 17 Aug 2021 06:32 |
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