Temperature-dependent tunneling electroresistance in Pt/BaTiO_3/SrRuO_3 ferroelectric tunnel junctions

摘要

Tunneling electroresistance of Pt/BaTiO_3/SrRuO_3 ferroelectric tunnel junctions is investigated as a function of temperature. Two distinct resistance states that are dependent on polarization direction in the BaTiO_3 barrier layer and bipolar resistance switching are observed at various temperatures from 10 to 290 K. The ON/OFF current ratio of Pt/BaTiO_3/SrRuO_3 tunnel junctions increases monotonically with decreasing temperature above 50 K and saturates below 50 K. The enhanced tunneling electroresistance at low temperatures can be ascribed to the suppression of thermally assisted indirect tunneling, which is less sensitive to the polarization reversal of BaTiO_3 compared to the direct tunneling.