Nonlinear stress-strain behavior and stress-induced phase transitions in soft Pb(Zr<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:math>Ti<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mi>x</mml:mi></mml:msub></mml:math>)O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /

Identification of crystalline elastic anisotropy in PZT ceramics from in-situ blocking stress measurements High energy x-ray diffraction measurements of lattice strains were performed on a rhombohedral Lead Zirconate Titanate ceramic (PZT 55-45) under combinations of applied electric field and compressive stress. These measurements allow the construction of blocking stress curves for different sets of crystallographic orientations which reflect the single crystal elastic anisotropy. A micro-mechanical interpretation of the results is then proposed. Assuming cubic symmetry for the crystalline elastic stiffness tensor and isotropy for the macroscopic elastic properties, the elastic properties of the single crystal are extracted from the measured data. An anisotropy ratio close to 0.3 is found (compared to 1 for isotropic materials). The high level of anisotropy found in this work suggests that crystalline elastic anisotropy should not be neglected in the modelling of ferroelectric materials.

Section: A Materials Preparation and Macroscopic Propertiessupporting

confidence: 58%

Section: Resultsmentioning

confidence: 80%

Identification of crystalline elastic anisotropy in PZT ceramics from in-situ blocking stress measurements

Daniel

Hall

Webber

et al. 2014

“…The order of magnitude of the Young's modulus seems reasonable and consistent with published data. 25,26 Following the same principle, apparent local material parameters can be identified. To be rigorously performed, however, this approach would need an appropriate micromechanical approach in order to define the electric field and stress in a given crystallographic orientation.…”

Section: Discussion On the Interpretation Of The Blocking Force Tmentioning

confidence: 99%

“…Such a phase transformation has been observed for the material of this study under the application of high compressive stress. 26 Fig. 19 shows the {200} and {111} peak profiles for w ¼ 0 under no applied electric field and for several levels of compressive stress.…”

Section: F Phase Changementioning

confidence: 99%

Revisiting the blocking force test on ferroelectric ceramics using high energy x-ray diffraction

Daniel

Hall

Koruza

et al. 2015

International audienceThe blocking force test is a standard test to characterise the properties of piezoelectric actuators. The aim of this study is to understand the various contributions to the macroscopic behaviour observed during this experiment that involves the intrinsic piezoelectric effect, ferroelectric domain switching, and internal stress development. For this purpose, a high energy diffraction experiment is performed in-situ during a blocking force test on a tetragonal lead zirconate titanate (PZT) ceramic (Pb 0.98 Ba 0.01 (Zr 0.51 Ti 0.49) 0.98 Nb 0.02 O 3). It is shown that the usual macroscopic linear interpretation of the test can also be performed at the single crystal scale, allowing the identification of local apparent piezoelectric and elastic properties. It is also shown that despite this apparent linearity, the blocking force test involves significant non-linear behaviour mostly due to domain switching under electric field and stress. Although affecting a limited volume fraction of the material, domain switching is responsible for a large part of the macroscopic strain and explains the high level of inter-and intra-granular stresses observed during the course of the experiment. The study shows that if apparent piezoelectric and elastic properties can be identified for PZT single crystals from blocking stress curves, they may be very different from the actual properties of polycrystalline materials due to the multiplicity of the physical mechanisms involved. These apparent properties can be used for macroscopic modelling purposes but should be considered with caution if a local analysis is aimed at

“…Previous characterization of the macroscopic electromechanical and stress--strain behavior has shown that uniaxial compressive stress can result in ferroelastic switching [22,23] as well as field--induced phase transitions in polycrystalline PZT. [24] Therefore, the primary aim of this work is to investigate role of stress on donor and acceptor--doped Pb(Zr,Ti)O3 through the characterization of the stress--and temperature--dependent direct piezoelectric response.…”

mentioning

confidence: 99%

Mechanical stability of piezoelectric properties in ferroelectric perovskites

Schader

Morozov

Wefring

et al. 2015

Self Cite

The influence of uniaxial compressive stress on the small signal direct piezoelectric coefficient of hard and soft Pb(Zr,Ti)O3 at the morphotropic phase boundary was investigated as a function of temperature from 25 °C to 450 °C. The stress--and temperature--dependent piezoelectric data indicate that stress is capable of either directly or indirectly modifying the orientation of polar defects in the crystal lattice. At higher temperatures, the mobility of polar defects was found to increase, corresponding to a two--step decrease in the direct piezoelectric coefficient and a decrease in the frequency dispersion. Quenching experiments were used to elucidate the role of the internal bias field on the stress--dependent piezoelectric response.