Impact of applied strain on the electron transport through ferroelectric

摘要

Combining nonequilibrium Green’s functions with density-functional theory, we have investigatednthe effect of external strain field on the tunneling electroresistance u0002TERu0003 of ferroelectric materialnsandwiched between Pt electrodes. The results show that the strain induced para/ferroelectric phasentransitions play an important role in the electronic transport properties of the junction. Sizablenenhancements in the resistance are found for the strained ferroelectric junctions with a TER ratio ofn9000%. Detail analyses show that the Ti–O displacements along the transport direction innferroelectric barrier change the effective potential profile, resulting in a giant piezoelectric resistancenin the ferroelectric tunnel junctions. © 2010 American Institute of Physics. u0004doi:10.1063/1.3462070