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BaTiO3 thin films with different annealing times were grown on LSMO/STO (001) substrates by pulsed laser deposition. An interesting phenomenon of loss-and-reappearance of the interfacial layer in BaTiO3 was detected in the x-ray diffraction results, and the ordered–unordered–ordered lattice transformation caused by oxygen vacancies’ filling was thought to be the reason. The ferroelectric domain was also confirmed to form during such an annealing process according to the piezoresponse force microscopy, transmission electron microscopy, and phase-field simulation. A Ti-displacement-rotation region considered an intermediate structure during the domain formation was observed at the interfacial layer of the 5.5-min-annealing film. Because of the oxygen deficiency and the effect of ferroelectric domain modulation of the built-in barrier height, a good memristive behavior with a resistive switching ratio of 1916 was obtained in the 10-min-annealing BaTiO3 (BTO) film, offering an avenue toward the application of oxygen-deficient BTO in neural network applications.

BaTiO3 thin films with different annealing times were grown on LSMO/STO (001) substrates by pulsed laser deposition. An interesting phenomenon of loss-and-reappearance of the interfacial layer in BaTiO3 was detected in the x-ray diffraction results, and the ordered–unordered–ordered lattice transformation caused by oxygen vacancies' filling was thought to be the reason. The ferroelectric domain was also confirmed to form during such an annealing process according to the piezoresponse force microscopy, transmission electron microscopy, and phase-field simulation. A Ti-displacement-rotation region considered an intermediate structure during the domain formation was observed at the interfacial layer of the 5.5-min-annealing film. Because of the oxygen deficiency and the effect of ferroelectric domain modulation of the built-in barrier height, a good memristive behavior with a resistive switching ratio of 1916 was obtained in the 10-min-annealing BaTiO3 (BTO) film, offering an avenue toward the application of oxygen-deficient BTO in neural network applications. [ABSTRACT FROM AUTHOR]

All-oxide free-standing cantilevers were fabricated with epitaxial (001)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) and Pb(Zr0.52Ti0.48)0.99Nb0.01O3 (PNZT) as piezoelectric layers and SrRuO3 electrodes. The ferroelectric and piezoelectric hysteresis loops were measured. From the zero-bias values, the figure-of-merits (FOMs) for piezoelectric energy harvesting systems were calculated. For the PNZT cantilever, an extremely large value FOM = 55 GPa was obtained. This very high value is due to the large shifts of the hysteresis loops such that the zero-bias piezoelectric coefficient e31f is maximum and the zero-bias dielectric constant is strongly reduced compared to the value in the undoped PZT device. The results show that by engineering the self-bias field the energy-harvesting properties of piezoelectric systems can be increased significantly.

Pb0.9La0.1(Zr0.52Ti0.48)O3 (PLZT) relaxor-ferroelectric thin films were grown on SrRuO3/SrTiO3/Si substrates by pulsed laser deposition. A large recoverable storage density (Ureco) of 13.7 J/cm3 together with a high energy efficiency (η) of 88.2% under an applied electric field of 1000 kV/cm and at 1 kHz frequency was obtained in 300-nm-thick epitaxial PLZT thin films. These high values are due to the slim and asymmetric hysteresis loop when compared to the values in the reference undoped epitaxial lead zirconate titanate Pb(Zr0.52Ti0.48)O3 ferroelectric thin films (Ureco = 9.2 J/cm3 and η = 56.4%) which have a high remanent polarization and a small shift in the hysteresis loop, under the same electric field.

All-oxide free-standing cantilevers were fabricated with epitaxial (001)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) and Pb(Zr0.52Ti0.48)0.99Nb0.01O3 (PNZT) as piezoelectric layers and SrRuO3 electrodes. The ferroelectric and piezoelectric hysteresis loops were measured. From the zero-bias values, the figure-of-merits (FOMs) for piezoelectric energy harvesting systems were calculated. For the PNZT cantilever, an extremely large value FOM = 55 GPa was obtained. This very high value is due to the large shifts of the hysteresis loops such that the zero-bias piezoelectric coefficient e31f is maximum and the zero-bias dielectric constant is strongly reduced compared to the value in the undoped PZT device. The results show that by engineering the self-bias field the energy-harvesting properties of piezoelectric systems can be increased significantly. [ABSTRACT FROM AUTHOR]

Pb0.9La0.1(Zr0.52Ti0.48)O3 (PLZT) relaxor-ferroelectric thin films were grown on SrRuO3/SrTiO3/Si substrates by pulsed laser deposition. A large recoverable storage density (Ureco) of 13.7 J/cm³ together with a high energy efficiency (η) of 88.2% under an applied electric field of 1000 kV/cm and at 1 kHz frequency was obtained in 300-nm-thick epitaxial PLZT thin films. These high values are due to the slim and asymmetric hysteresis loop when compared to the values in the reference undoped epitaxial lead zirconate titanate Pb(Zr0.52Ti0.48)O3 ferroelectric thin films (Ureco = 9.2 J/cm³ and η = 56.4%) which have a high remanent polarization and a small shift in the hysteresis loop, under the same electric field. [ABSTRACT FROM AUTHOR]