Leakage mechanisms in BiFeO3 thin films

Abstract

The authors report results of transport studies on high quality, fully epitaxial BiFeO3 thin films grown via pulsed laser deposition on SrRuO3∕DyScO3 (110) substrates. Ferroelectric tests were conducted using symmetric and asymmetric device structures with either SrRuO3 or Pt top electrodes and SrRuO3 bottom electrodes. Comparison between these structures demonstrates the influence of electrode selection on the dominant transport mechanism. Analysis of film electrical response suggests Poole-Frenkel emission as the limiting leakage current mechanism in the symmetric structure. Temperature dependent measurements yield trap ionization energies of ∼0.65–0.8eV. No clear dominant leakage mechanism was observed for the asymmetric structure.

Structural, magnetic and dielectric properties of nano-crystalline Ni-doped BiFeO3 ceramics formulated by self-propagating high-temperature synthesis

“…To overcome this problem, various approaches have been proposed, such as reduction in oxygen vacancies, domination of the ohmic conduction, and intergrain depletion in grain boundary limited conduction. The efforts have been made to reduce the leakage current density by either introducing dopants or using different fabrication methods [12][13][14][15][16]. At present, many researchers are engaged in the enrichment of multiferroic properties of BiFeO 3 -relevant materials, using different trivalent dopants such as La [17], Mn [18], Sm [19] and Ti [20].…”

Electrical Processes in Polycrystalline BiFeO3 Film

“…However, there is an obvious difference between the experimental results of epitaxial and polycrystalline films. For epitaxial BFO films, the slope of the line log(σ) vs. 1000/T varies linearly with the applied voltage (Pabst, 2007). But the slope of the lines in Fig.…”

“…V is the voltage applied on the BFO film and d is the thickness of the BFO film. According to Pabst's report, the PF emission is the dominant transport mechanism in epitaxial BFO films (Pabst, 2007). Therefore, it is reasonable that PF emission is also one of the dominant leakage mechanisms in polycrystalline BFO film.…”

“…In the semi-log plot, the relationship between the conductance and the reciprocal of temperature is approximately linear. This relationship follows the Poole-Frenkel (PF) emission (Pabst, 2007;, which can be expressed as 3 0 1 exp…”

“…More studies on BFO films are carried out (Eerenstein, 2005;Zavaliche, 2005;Hauser, 2008;Liu, 2008;. Even though the leakage mechanism in epitaxial BFO film has been studied (Pabst, 2007), the higher leakage current is still an obstacle for the study and application of polycrystalline BFO films. Compared to the epitaxial BFO films grown on perovskite structure substrate, the applications of polycrystalline BFO on silicon wafer are broader in the field of microelectronic devices.…”