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Temperature dependent mechanical property of PZT film: an investigation by nanoindentation.

Li Y, Feng S, Wu W, Li F - PLoS ONE (2015)

Bottom Line: Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method.Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature.The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains.

View Article: PubMed Central - PubMed

Affiliation: Department of Engineering mechanics, School of Civil Engineering, Wuhan University, Wuhan, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China.

ABSTRACT
Load-depth curves of an unpoled Lead Zirconate Titanate (PZT) film composite as a function of temperature were measured by nanoindentation technique. Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method. Then the true modulus and hardness of the PZT film were assessed by decoupling the influence of substrate using methods proposed by Zhou et al. and Korsunsky et al., respectively. Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature. The increasing of indentation depth and the decreasing of hardness are thought to be caused by the decreasing of the critical stress needed to excite dislocation initiation at high temperature. The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains. The influence of residual stress on the indentation behavior of PZT film composite was also investigated by measuring its load-depth curves with pre-load strains.

No MeSH data available.


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The electric field vs. polarization curves of PZT film as a function of electric field amplitude.The inset figure illustrates the inhomogeneous structure of the tested PZT film composite.
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pone.0116478.g001: The electric field vs. polarization curves of PZT film as a function of electric field amplitude.The inset figure illustrates the inhomogeneous structure of the tested PZT film composite.

Mentions: This investigation was performed on a commercial available PZT film composite provided by Inostek Inc. (South Korea). It was prepared by traditional sol-gel method on Pt(150nm)/Ti(10nm)/SiO2(300nm)/Si(<100> P type) substrate with thickness of 500nm (Fig. 1) [26,27]. As the texture of Pt is (111), the texture of the PZT film is (111) also due to the fact that the activation energy needed for PZT nucleation is the lowest on lattice matched substrate [27]. The Zr/Ti ratio of the material is 53/47, and thus according to the previous report [27], its crystal structure is in the vicinity of morphtropic boundary in the tetragonal range. Its coercive electric fields and remnant polarization are 4.8kV/mm and 28μC/cm2, respectively. Fig. 1 shows its electric field vs. polarization curves under cyclic electric fields loading with different amplitude measured by Sawyer-Tower circuit [2]. It can be seen that the switchable polarizations increase with the increasing of electric field amplitude, indicating that more domains can be switched under large electric fields.


Temperature dependent mechanical property of PZT film: an investigation by nanoindentation.

Li Y, Feng S, Wu W, Li F - PLoS ONE (2015)

The electric field vs. polarization curves of PZT film as a function of electric field amplitude.The inset figure illustrates the inhomogeneous structure of the tested PZT film composite.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358891&req=5

pone.0116478.g001: The electric field vs. polarization curves of PZT film as a function of electric field amplitude.The inset figure illustrates the inhomogeneous structure of the tested PZT film composite.
Mentions: This investigation was performed on a commercial available PZT film composite provided by Inostek Inc. (South Korea). It was prepared by traditional sol-gel method on Pt(150nm)/Ti(10nm)/SiO2(300nm)/Si(<100> P type) substrate with thickness of 500nm (Fig. 1) [26,27]. As the texture of Pt is (111), the texture of the PZT film is (111) also due to the fact that the activation energy needed for PZT nucleation is the lowest on lattice matched substrate [27]. The Zr/Ti ratio of the material is 53/47, and thus according to the previous report [27], its crystal structure is in the vicinity of morphtropic boundary in the tetragonal range. Its coercive electric fields and remnant polarization are 4.8kV/mm and 28μC/cm2, respectively. Fig. 1 shows its electric field vs. polarization curves under cyclic electric fields loading with different amplitude measured by Sawyer-Tower circuit [2]. It can be seen that the switchable polarizations increase with the increasing of electric field amplitude, indicating that more domains can be switched under large electric fields.

Bottom Line: Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method.Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature.The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains.

View Article: PubMed Central - PubMed

Affiliation: Department of Engineering mechanics, School of Civil Engineering, Wuhan University, Wuhan, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China.

ABSTRACT
Load-depth curves of an unpoled Lead Zirconate Titanate (PZT) film composite as a function of temperature were measured by nanoindentation technique. Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method. Then the true modulus and hardness of the PZT film were assessed by decoupling the influence of substrate using methods proposed by Zhou et al. and Korsunsky et al., respectively. Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature. The increasing of indentation depth and the decreasing of hardness are thought to be caused by the decreasing of the critical stress needed to excite dislocation initiation at high temperature. The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains. The influence of residual stress on the indentation behavior of PZT film composite was also investigated by measuring its load-depth curves with pre-load strains.

No MeSH data available.


Related in: MedlinePlus