Uncovering the symmetry of the induced ferroelectric phase transformation in polycrystalline barium titanate

Abstract The effects of 1-nm-thick CeOx capping on 7.5-nm-thick Y-doped HfO2 films on the ferroelectric characteristics are investigated. From the ferroelectric characteristics of the samples annealed at different temperatures from 450 to 600oC and annealing durations, the time (τ) required to stabilize the ferroelectric phase at each temperature was shortened by the capping. The identical activation energy (Ea) of 2.65 eV for ferroelectric stabilization without and with capping suggests the same kinetics for phase transformation. However, an increase in the remnant polarization (Pr) was obtained. Only a few Ce atoms diffused into the underlying HfO2 film even after 600oC annealing. Ferroelectric switching tests revealed an improvement in endurance from 107 to 1010 by the capping, presumably owing to the suppression of conductive filament formation. Therefore, CeOx capping is effective in promoting the ferroelectric phase in HfO2 with high switching endurance.

Download Full-text

Oxygen Displacement through the Ferroelectric Phase Transition of Barium Titanate-High-Temperature 17O NMR

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1994.tb04581.x ◽

1994 ◽

Vol 77 (12) ◽

pp. 3263-3266 ◽

Cited By ~ 9

Author(s):

Dane R. Spearing ◽

Jonathan F. Stebbins

Keyword(s):

Phase Transition ◽

High Temperature ◽

Barium Titanate ◽

Ferroelectric Phase Transition ◽

Ferroelectric Phase ◽

17O Nmr

Download Full-text

A Novel Technique for Determining Local Dielectric Function During Ferroelectric to Paraelectric Phase Transformation in Barium Titanate with a Transmission Eels

MRS Proceedings ◽

10.1557/proc-404-101 ◽

1995 ◽

Vol 404 ◽

Author(s):

Kalpana S Katti ◽

Maoxu Qian ◽

Mehmet Sarikaya

Keyword(s):

Phase Transformation ◽

Barium Titanate ◽

Energy Loss ◽

Electron Energy ◽

Dielectric Function ◽

Optical Parameters ◽

Edge Structure ◽

Transmission Electron ◽

Electron Energy Loss

AbstractIn this work a transmission electron microscopy (TEM) technique was used in obtaining local dielectric properties calculated from optical parameters for dynamic investigation of the effect of cubic to tetragonal phase transformation in barium titanate. In order to obtain in situ local dielectric during phase transformation, Kramers-Kronig relations were applied using the transmission electron energy loss (EELS) measurements. The optical excitations in the EELS spectra were consistent with the band structure results. The Re (1/ε) (real part of the dielectric function) obtained from the energy loss data indicated a change at the phase transformation. A broadening of the valence plasmon excitation suggested an order-disorder nature to the cubic to tetragonal transformation. In situ electron energy loss near edge structure (ELNES) studies from 500–700 eV energy range near the O-K edge exhibited a pre-edge feature that is associated with the Ti-L1, edge which further indicates an order-disorder nature to the phase transformation. The significance of the results is discussed.

Download Full-text

Low-temperature crystallization and paraelectric–ferroelectric phase transformation in nanoscale ZrO2 thin films induced by atomic layer plasma treatment

Journal of Materials Chemistry C ◽

10.1039/c9tc04801d ◽

2020 ◽

Vol 8 (11) ◽

pp. 3669-3677

Author(s):

Sheng-Han Yi ◽

Kuei-Wen Huang ◽

Hsin-Chih Lin ◽

Miin-Jang Chen

Keyword(s):

Thin Films ◽

Phase Transformation ◽

Low Temperature ◽

Plasma Treatment ◽

Ferroelectric Phase ◽

Atomic Layer ◽

Treatment Technique ◽

Low Temperature Crystallization ◽

Temperature Crystallization

Crystallization and ferroelectricity with high endurance are achieved in ZrO2 thin films at low temperature using an atomic layer plasma treatment technique.

Download Full-text