Leakage mechanisms in BiFe O3 thin films

The authors report results of transport studies on high quality, fully epitaxial BiFe O3 thin films grown via pulsed laser deposition on SrRu O3 DySc O3 (110) substrates. Ferroelectric tests were conducted using symmetric and asymmetric device structures with either SrRu O3 or Pt top electrodes and SrRu O3 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 ∼0.65-0.8 eV. No clear dominant leakage mechanism was observed for the asymmetric structure. © 2007 American Institute of Physics.