First principles study of hydrogen in lead zirconate titanate

First principles investigations, including density functional theory (DFT) have been applied to calculate the electronic properties of A-site modified lead zirconate titanate (PZT). The theoretical explanation for the origin of fatigue in ferroelectric perovskite oxides was implemented to study the fatigue behavior. The explanation indicates that, the fatigue is related to the weakness of π bond between Ti 3d and O 2p states, caused by the occupancy of the Ti 3d state by electrons which released from oxygen vacancies. If a certain energy state of the additive element founded to be overlapped with the Ti 3d state at conduction band minima, then it will sharing the electrons released by oxygen vacancies with the Ti 3d state. Therefore, when the Ti 3d state become less occupied with electrons the π bond between the Ti 3d and O 2p states become more maintained and the composition is less susceptible to fatigue.

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Comparisons of Piezoelectricities of Lead Zirconate Titanate for Various Phases by a First-Principles Method

Japanese Journal of Applied Physics ◽

10.1143/jjap.46.5199 ◽

2007 ◽

Vol 46 (8A) ◽

pp. 5199-5204 ◽

Cited By ~ 3

Author(s):

Yukihiro Okuno ◽

Koji Kawato ◽

Masayuki Suzuki ◽

Akinori Harada ◽

Tamio Oguchi

Keyword(s):

Lead Zirconate Titanate ◽

First Principles ◽

Lead Zirconate ◽

Zirconate Titanate ◽

First Principles Method

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Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143961 ◽

1986 ◽

Vol 44 ◽

pp. 482-483

Author(s):

M.L.A. Dass ◽

T.A. Bielicki ◽

G. Thomas ◽

T. Yamamoto ◽

K. Okazaki

Keyword(s):

Lead Zirconate Titanate ◽

Direct Proof ◽

Lead Zirconate ◽

Subsolidus Phase ◽

Pzt Ceramics ◽

Subsolidus Phase Diagram ◽

Zirconate Titanate ◽

Two Phases ◽

Cbd Method ◽

Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

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