Rotational instability of the electric polarization and divergence of the shear elastic compliance

Cordero, F.; Langhammer, H. T.; Müller, Thomas; Buscaglia, Vincenzo; Nanni, Paolo

doi:10.1103/physrevb.93.064111

Cited by 15 publications

(21 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The technique provides not only the Young's modulus but also internal friction, which reflect the dynamics of point and extended defects like the ferroelectric/ferroelastic domain walls [16][17][18][19]. We report here the application of DMA to the study of KNN-based materials.…”

Section: Introductionmentioning

confidence: 99%

Origin of discrepancy between electrical and mechanical anomalies in lead-free (K,Na)NbO3 -based ceramics

et al. 2016

View full text Add to dashboard Cite

Ferroelectric polymorphic phase coexistence, associated with either the presence of a morphotropic phase boundary or a temperature-driven polymorphic phase transition, is currently acknowledged as the key to high piezoelectric activity and is searched when new perovskite materials are developed, like lead-free alternatives to state-of-the-art Pb(Zr,Ti)O 3 . This requires characterization tools that allow phase coexistence and transitions to be readily identified, among which measurements of the temperature dependences of Young's modulus and mechanical losses by dynamical mechanical analysis stand out as a powerful technique to complement standard electrical characterizations. We report here the application of this technique to (K 1−x Na x )NbO 3 -based materials, which are under extensive investigation as environmentally friendly high sensitivity piezoelectrics. The elastic anomalies associated with the different phase transitions are identified and are shown to be distinctively shifted in relation to the dielectric ones. The origin of this discrepancy is discussed with the help of temperature-dependent Raman spectroscopy and is proposed to be a characteristic of diffuse phase transitions.

show abstract

Section: Introductionmentioning

confidence: 99%

Origin of discrepancy between electrical and mechanical anomalies in lead-free (K,Na)NbO3 -based ceramics

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The ceramic BaTiO 3 samples were prepared by conventional solid state reaction in different laboratories, as described in Ref. 5…”

Section: Methodsmentioning

confidence: 99%

Piezoelectricity from Elastic and Dielectric Measurements on Unpoled Ferroelectrics

Cordero

2018

Mat. Res.

View full text Add to dashboard Cite

A method is described to assess the piezoelectric response of ferroelectric materials from the temperature dependence of the elastic moduli and dielectric constant of unpoled samples. The limits and advantages over the traditional methods on poled samples are discussed. A quantitative check is made by comparing the piezoelectric softening measured below the ferroelectric transition in the Young's modulus of unpoled ceramic BaTiO 3 , with the appropriate angular average of the single crystal material constants from the literature. The softening effect of porosity has been taken into account by comparing the moduli of samples with different densities.

show abstract

“…It is true that also the calculated curves do not agree with each other, but there seems to be a systematic difference between the temperature dependencies of the measured and calculated piezoelectric softenings. The motion of domain walls may also be responsible for such deviations, but the analysis of the s (T) and elastic energy loss curves measured at different frequencies [40] suggests that the contribution of DW relaxation is negligible, at least in curves 2 and 3. It can be concluded that, at least in a limited temperature region below T C where complications from fluctuations and multiple FE transitions are excluded, there is quantitative agreement between the piezoelectric softening measured on unpoled ceramic BaTiO 3 and that calculated from the known piezoelectric and dielectric tensors.…”

Section: Experimental Verification and Porositymentioning

confidence: 99%

Elastic and Dielectric Evaluation of the Piezoelectric Response of Ferroelectrics Using Unpoled Ceramics

Cordero¹

2018

Preprint

View full text Add to dashboard Cite

The evaluation of the piezoelectric properties of ferroelectric ceramics generally has a high level of uncertainty, due to incomplete poling, porosity, domain wall clamping and other effects. In addition, the poling process is often difficult and dangerous, due to the risk of breaking or damaging the sample. A method is described for the evaluation of the potential intrinsic piezoelectric response that a ceramic would have after full poling, without poling it. The method relies on the fact that any material undergoes an elastic softening below the ferroelectric transition temperature, whose magnitude can be expressed in terms of the intrinsic piezoelectric and dielectric coefficients of the material. Such a softening is equivalent to an electromechanical coupling, averaged over all the components due to the unpoled state of the sample, and can be deduced from a single temperature scan of an elastic modulus of a ceramic sample, spanning the ferroelectric and paraelectric states. The strengths, limits and possible applications of the method are discussed.

show abstract

Rotational instability of the electric polarization and divergence of the shear elastic compliance

Cited by 15 publications

References 51 publications

Origin of discrepancy between electrical and mechanical anomalies in lead-free (K,Na)NbO3 -based ceramics

Origin of discrepancy between electrical and mechanical anomalies in lead-free (K,Na)NbO3 -based ceramics

Piezoelectricity from Elastic and Dielectric Measurements on Unpoled Ferroelectrics

Elastic and Dielectric Evaluation of the Piezoelectric Response of Ferroelectrics Using Unpoled Ceramics

Contact Info

Product

Resources

About