Critical properties of nanoscale asymmetric ferroelectric tunnel junctions or capacitors

An Epitaxial Ferroelectric Tunnel Junction on Silicon

“…[ 28 ] Meanwhile, the average potential barrier height U Up (0.79 eV) for the polarization up-state is larger than U Down (0.46 eV) for polarization-down. This fact makes the conductance for polarization-down much larger than that for polarization-up, resulting in the observed TER effect.…”

Effect of a built-in electric field in asymmetric ferroelectric tunnel junctions

“…We neglect the energy difference of the asymmetric surfaces, i.e., by setting ζ 1 = ζ 2 , η 1 = η 2 , to ensure that the effect of E bi is clearly observable from the calculations since it is reported that surface effects are generally much smaller than that of E bi . 36,37 All the parameters we used are listed in Ref. 65.…”

“…[29][30][31][32][33][34] However, recent theoretical studies suggest that the choice of electrode material may lead to smearing of size effect or even vanishing of h c . [35][36][37][38][39] For example, it was reported that choosing Pt as electrodes would induce a strong interfacial enhancement of the ferroelectricity in Pt/BaTiO 3 (BTO)/Pt FTJs, where h c is only an 0.08 BTO unit cell. 35 In addition, the results of a modified thermodynamic model 36,37 and first-principles calculations 38,39 both indicate that the BTO barrier with dissimilar electrodes, i.e., Pt and SrRuO 3 (SRO) electrodes, might be free of deleterious size effects.…”

“…[35][36][37][38][39] For example, it was reported that choosing Pt as electrodes would induce a strong interfacial enhancement of the ferroelectricity in Pt/BaTiO 3 (BTO)/Pt FTJs, where h c is only an 0.08 BTO unit cell. 35 In addition, the results of a modified thermodynamic model 36,37 and first-principles calculations 38,39 both indicate that the BTO barrier with dissimilar electrodes, i.e., Pt and SrRuO 3 (SRO) electrodes, might be free of deleterious size effects. In contrast, it has been reported that asymmetric combination of the electrodes (including the same electrodes with different terminations) will result in the destabilization of one polarization state making the asymmetric FTJs non-FE.…”

The physical nature of bipolar resistive switching in Pt/BiFe0.95Mn0.05O3/Pt memory devices

“…Multiferroic bismuth ferrite (BFO) has attracted a tremendous flurry of research interest for its promising potential in novel multifunctional device applications . BFO is reported to possess remarkable properties including ferroelectricity and antiferromagnetism with a high Curie temperature ( T C ) , a high Néel temperature ( T N ) , and a large remnant polarization (∼100 µC cm −2 ) .…”