钛含量对PZT/STO铁电电容器隧穿电阻的影响

Effects of Ti contents to the tunneling electroresistance of PZT/STO ferroelectric capacitors

采用Landau-Devonshire自由能理论和晶格模型,研究了PbZr1-xTixO3(PZT)/SrTiO3(STO)复合薄膜中PZT的钛(Ti)含量(x=0.5,0.6,0.8,1.0)对铁电隧道结极化强度、总电势、电导和隧穿电阻等的影响,从而增大隧穿电阻.模拟结果表明:随着层数增加,复合薄膜极化强度增大;随着Ti含量增加,隧道结电导先减小后增大,其隧穿电阻率先增大后减小;PZT极化强度、STO总电势和PZT总电势的斜率均在x=0.8时最大.

Applying Landau-Devonshire free energy theory and lattice model, the effects of different Ti contents（x = 0. 5,0. 6,0. 8,1.0） of the PbZr1-x, TixO3 （PZT） in the PZT/SrTiO3 （STO） composite films on the intensity of polarization, total electric potential, conductance and tunneling electroresistance in the ferroelectric tunnel junction have been discussed. The results show that as the number of layers increases, the intensity of polarization of PZT increases. And as Ti contents increase, the intensity of polarization of PZT increases, and conductance shows a trend of first decrease and then increase, and tunneling electrore-sistance shows a trend of first increase and then decrease. The intensity of polarization of PZT, total electric potential of STO and slope of total electric potential of PZT are the biggest when x=0.8.