Temperature-dependent leakage mechanisms of Pt∕BiFeO3∕SrRuO3 thin film capacitors

Abstract

Epitaxial c-axis oriented BiFeO3 (BFO) thin films were deposited on conductive SrRuO3 (SRO) on (001) SrTiO3 substrates by pulsed laser deposition. A Pt/BFO/SRO capacitor was constructed by depositing a top Pt electrode. The leakage current density versus. electric field characteristics were investigated from 80to350K. It was found that the leakage mechanisms were a strong function of temperature and voltage polarity. At temperatures between 80 and 150K, space-charge-limited current was the dominant leakage mechanism for both negative and positive biases. On the other hand, at temperatures between 200 and 350K the dominant leakage mechanisms were Poole-Frenkle emission and Fowler-Nordheim tunneling for negative and positive biases, respectively.

Surface phase, morphology, and charge distribution transitions on vacuum and ambient annealedSrTiO3(100)

“…[ [3][4][5][6][7][8] In addition, FeSe thin films grown on SrTiO 3 have recently attracted attention due to their display of interfacial high temperature superconductivity, which has been associated with charge transfer to FeSe from Ti +3 formed by surface reduction. [9][10][11][12][13] Ultimately, such studies attempt to enable improvements in device quality by correlating the physical properties of devices made from thin film heterostructures to the specifics of the bare substrate's surface termination, structure, and chemical state.…”

Giant magnetoelectric coupling interaction in BaTiO3/BiFeO3/BaTiO3 trilayer multiferroic heterostructures

“…Observed current density $ 10 À4 A/cm 2 were found to be in close agreement to the reported values. [15][16][17][18] Leakage current in BFO thin films is attributed to the valance fluctuation of Fe ions between Fe 2þ and Fe 3þ states and migration of oxygen vacancies toward electrode resulting into the conduction under high electric fields. 19 High substrate temperature ($650 C) and low oxygen partial pressure ($10 À2 Torr) results in the formation of oxygen vacancies in trilayer films during sputtering.…”

2D Nanovaristors at Grain Boundaries Account for Memristive Switching in Polycrystalline BiFeO3

“…When an electric field is applied at room temperature, Poole-Frenkel emission [32,33] occurs at oxygen vacancies (the electric field lowers the ionization energy). Subsequent non-radiative capture amounts to the capture energy (0.6 or 1.6 eV in the present cases) being converted to mostly localized phonons, known as a "phonon kick" which leads to what is known as recombination-enhanced migration [22].…”