Leakage mechanisms in bismuth ferrite-lead titanate thin films on Pt/Si substrates

摘要

(1 -x)BiFeO_3-xpbTiO_3 (0.5 < x < 0.3) thin films have been reported to exhibit high remanent polarizations but device integration is hindered by the presence of leakage currents. An insight into the nature of leakage mechanisms in the films is presented. Films with x=0.4 and 0.5 exhibit lower leakage currents as compared to x=0.3 films. At applied fields above 190 kV cm~(-1), in the region of the coercive field of these films, x=0.4 and 0.5 exhibit a Poole-Frenkel mechanism while films with x=0.3 exhibit a combination of space charge limited current and the Schottky effect.