Poole-Frenkel effect and variable-range hopping conduction in metal/YBCO resistive switching devices

A. SCHULMAN; L. F.LANOSA; C. ACHA

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 2015 vol. 118 p. 445111 - 445116

0021-8979

Current-voltage (IV) characteristics and the temperature dependence of the contact resistance [R(T)]of Au/YBa2Cu3O7d (optimally doped YBCO) interfaces have been studied at different resistancestates. These states were produced by resistive switching after accumulating cyclic electrical pulsesof increasing number and voltage amplitude. The IV characteristics and the R(T) dependence of thedifferent states are consistent with a Poole-Frenkel (P-F) emission mechanism with trapping-energylevels Et in the 0.06?0.11 eV range. Et remains constant up to a number-of-pulses-dependent criticalvoltage and increases linearly with a further increase in the voltage amplitude of the pulses. The observationof a P-F mechanism reveals the existence of an oxygen-depleted layer of YBCO near theinterface. A simple electrical transport scenario is discussed, where the degree of disorder, the trapenergy level, and the temperature range determine an electrical conduction dominated by non-lineareffects, either in a P-F emission or in a variable-range hopping regime.VC