scholarly journals Piezoelectricity in hafnia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sangita Dutta ◽  
Pratyush Buragohain ◽  
Sebastjan Glinsek ◽  
Claudia Richter ◽  
Hugo Aramberri ◽  
...  
Keyword(s):  
First Principles ◽  
Piezoelectric Effect ◽  
Piezoresponse Force Microscopy ◽  
Perovskite Oxides ◽  
Ferroelectric Material ◽  
Active Oxygen ◽  
Piezoelectric Response ◽  
First Principles Calculations ◽  
Force Microscopy ◽  
Epitaxial Strain

AbstractBecause of its compatibility with semiconductor-based technologies, hafnia (HfO2) is today’s most promising ferroelectric material for applications in electronics. Yet, knowledge on the ferroic and electromechanical response properties of this all-important compound is still lacking. Interestingly, HfO2 has recently been predicted to display a negative longitudinal piezoelectric effect, which sets it apart from classic ferroelectrics (e.g., perovskite oxides like PbTiO3) and is reminiscent of the behavior of some organic compounds. The present work corroborates this behavior, by first-principles calculations and an experimental investigation of HfO2 thin films using piezoresponse force microscopy. Further, the simulations show how the chemical coordination of the active oxygen atoms is responsible for the negative longitudinal piezoelectric effect. Building on these insights, it is predicted that, by controlling the environment of such active oxygens (e.g., by means of an epitaxial strain), it is possible to change the sign of the piezoelectric response of the material.

Surface displacements and surface charges on Ba2CuWO6 and Ba2Cu0.5Zn0.5WO6 ceramics induced by local electric fields investigated with scanning-probe microscopy

2007 ◽  
Vol 22 (1) ◽  
pp. 193-200
Author(s):  
Ralf-Peter Herber ◽  
Gerold A. Schneider
Keyword(s):  
Electric Fields ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Ferroelectric Material ◽  
Relaxor Ferroelectrics ◽  
Surface Charges ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Displacements

Ba2CuWO6 (BCW) was first synthesized in the mid 1960s, and it was predicted to be a ferroelectric material with a very high Curie temperature of 1200 °C [N. Venevtsev and A.G. Kapyshev: New ferroelectrics. Proc. Int. Meet. Ferroelectr.1, 261 (1966)]. Since then, crystallographic studies were performed on the compound with the result that its crystal structure is centrosymmetric. Thus for principal reason, BCW cannot be ferroelectric. That obvious contradiction was examined in this study. Disk-shaped ceramic samples of BCW and Ba2Cu0.5Zn0.5WO6 (BCZW) were prepared. Because of the low electrical resistivity of the ceramics, it was not possible to perform a typical polariszation hysteresis loop for characterization of ferroelectric properties. Scanning electron microscopy investigations strongly suggest that the reason for the conductivity is found in the impurities/precipitations within the microstructure of the samples. With atomic force microscopy (AFM) in piezoresponse force microscopy (PFM) mode, it is possible to characterize local piezoelectricity by imaging the ferroelectric domains. Neither BCW nor BCZW showed any domain structure. Nevertheless, when local electric fields were applied to the surfaces of the ceramics topographic displacements, imaged with AFM, and surface charges, imaged with Kelvin probe force microscopy (KFM) and PFM, were measured and remained stable on the surface for the time of the experiment. Therefore BCW and BCZW are considered to be electrets and possibly relaxor ferroelectrics.

Nanoelectromechanics of Piezoresponse Force Microscopy: Contact Properties, Fields Below the Surface and Polarization Switching

2003 ◽  
Vol 784 ◽  
Author(s):  
S. V. Kalinin ◽  
Junsoo Shin ◽  
M. Kachanov ◽  
E. Karapetian ◽  
A. P. Baddorf
Keyword(s):  
Strain Distribution ◽  
Point Charge ◽  
Closed Form Solution ◽  
Piezoresponse Force Microscopy ◽  
Polarization Switching ◽  
Ferroelectric Material ◽  
Form Solution ◽  
Force Microscopy ◽  
Force Magnitude ◽  
Resolution Limits

ABSTRACTTo achieve quantitative interpretation of Piezoresponse Force Microscopy (PFM), including resolution limits, tip bias- and strain-induced phenomena and spectroscopy, knowledge of elastic and electrostatic field distributions below the tip is required. The exact closed form solution of the coupled electroelastic problem for piezoelectric indentation is derived and used to obtain the tip-induced electric field and strain distribution in the ferroelectric material. This establishes a complete continuum mechanics description of the PFM imaging mechanism. These solutions are reduced to the point charge/force behavior for large separations from contact, and the applicability limits and charge/force magnitude for these models are established. The implications of these results for ferroelectric polarization switching processes are analyzed.

The Microstructure and Local Piezoelectric Response in Polymer Nanocomposites with Different Ferroelectric Crystalline Additions

2013 ◽  
Vol 1556 ◽  
Author(s):  
Dmitry A. Kiselev ◽  
Mikhail D. Malinkovich ◽  
Yuriy N. Parkhomenko ◽  
Alexandr V. Solnyshkin ◽  
Alexey A. Bogomolov ◽  
...  
Keyword(s):  
Electric Fields ◽  
Piezoelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Piezoelectric Response ◽  
Relaxation Dynamics ◽  
Force Microscopy ◽  
Nanostructured Polymer ◽  
Ferroelectric Domains ◽  
Resolution Imaging ◽  
Local Polarization

ABSTRACTIn this work, we report on local ferroelectric and piezoelectric properties of nanostructured polymer composites P(VDF-TrFE)+x(Ba,Pb)(Zr,Ti)O3 (x = 0 - 50 %). High-resolution imaging of ferroelectric domains, local polarization switching, and polarization relaxation dynamics were studied by piezoresponse force microscopy. In particular, we found that (Ba,Pb)(Zr,Ti)O3 inclusions usually show a strong unipolar piezoresponse signal, as compared to the polymer matrix. By scanning under high dc voltage the films can be polarized uniformly under both positive and negative electric fields. Stability of the polarized state is discussed.

scholarly journals Strain-induced creation and switching of anion vacancy layers in perovskite oxynitrides

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Takafumi Yamamoto ◽  
Akira Chikamatsu ◽  
Shunsaku Kitagawa ◽  
Nana Izumo ◽  
Shunsuke Yamashita ◽  
...  
Keyword(s):  
First Principles ◽  
Lattice Strain ◽  
Anion Vacancy ◽  
Perovskite Oxides ◽  
Strain Effect ◽  
First Principles Calculations ◽  
Ammonia Treatment ◽  
Oxide Heterostructures ◽  
Thin Film Oxides ◽  
Order Pattern

AbstractPerovskite oxides can host various anion-vacancy orders, which greatly change their properties, but the order pattern is still difficult to manipulate. Separately, lattice strain between thin film oxides and a substrate induces improved functions and novel states of matter, while little attention has been paid to changes in chemical composition. Here we combine these two aspects to achieve strain-induced creation and switching of anion-vacancy patterns in perovskite films. Epitaxial SrVO3 films are topochemically converted to anion-deficient oxynitrides by ammonia treatment, where the direction or periodicity of defect planes is altered depending on the substrate employed, unlike the known change in crystal orientation. First-principles calculations verified its biaxial strain effect. Like oxide heterostructures, the oxynitride has a superlattice of insulating and metallic blocks. Given the abundance of perovskite families, this study provides new opportunities to design superlattices by chemically modifying simple perovskite oxides with tunable anion-vacancy patterns through epitaxial lattice strain.

scholarly journals Significant Enhancement of Piezoelectric Response in AlN by Yb Addition

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 309
Author(s):  
Kenji Hirata ◽  
Yuto Mori ◽  
Hiroshi Yamada ◽  
Masato Uehara ◽  
Sri Ayu Anggraini ◽  
...  
Keyword(s):  
First Principles ◽  
Electromechanical Coupling ◽  
Piezoelectric Response ◽  
Electromechanical Coupling Coefficient ◽  
Mixing Enthalpy ◽  
First Principles Calculations ◽  
Softening Effect ◽  
Wurtzite Phase ◽  
Salt Phase ◽  
High Concentrations

This study employs first-principles calculations to investigate how introducing Yb into aluminum nitride (AlN) leads to a large enhancement in the material’s piezoelectric response (d33). The maximum d33 is calculated to be over 100 pC/N, which is 20 times higher than that of AlN. One reason for such a significant improvement in d33 is the elastic-softening effect, which is indicated by a decrease in the elastic constant, C33. The strain sensitivity (du/dε) of the internal parameter, u, is also an important factor for improving the piezoelectric stress constant, e33. On the basis of mixing enthalpy calculations, YbxAl1−xN is predicted to be more stable as a wurtzite phase than as a rock salt phase at composition up to x ≈ 0.7. These results suggest that Yb can be doped into AlN at high concentrations. It was also observed that the dielectric constant, ε33, generally increases with increasing Yb concentrations. However, the electromechanical coupling coefficient, k332, only increases up to x = 0.778, which is likely because of the relatively lower values of ε33 within this range.

Electrochemical Atomic Force Microscopy and First-Principles Calculations of Ferriprotoporphyrin Adsorption and Polymerization

Langmuir ◽  
2018 ◽  
Vol 34 (38) ◽  
pp. 11335-11346
Author(s):  
Jason A. Bennett ◽  
Daniel P. Miller ◽  
Scott M. Simpson ◽  
Marcela Rodriguez ◽  
Eva Zurek
Keyword(s):  
Atomic Force Microscopy ◽  
First Principles ◽  
First Principles Calculations ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Local Piezoelectric Properties of Doped Biomolecular Crystals

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4922
Author(s):  
Andrei Kholkin ◽  
Denis Alikin ◽  
Vladimir Shur ◽  
Shiri Dishon ◽  
David Ehre ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Piezoelectric Properties ◽  
Dipole Moments ◽  
Mechanical Strain ◽  
Piezoresponse Force Microscopy ◽  
Piezoelectric Response ◽  
Force Microscopy ◽  
Highly Sensitive ◽  
Molecule Interactions ◽  
Co Doped

Piezoelectricity is the ability of certain crystals to generate mechanical strain proportional to an external electric field. Though many biomolecular crystals contain polar molecules, they are frequently centrosymmetric, signifying that the dipole moments of constituent molecules cancel each other. However, piezoelectricity can be induced by stereospecific doping leading to symmetry reduction. Here, we applied piezoresponse force microscopy (PFM), highly sensitive to local piezoelectricity, to characterize (01¯0) faces of a popular biomolecular material, α-glycine, doped with other amino acids such as L-alanine and L-threonine as well as co-doped with both. We show that, while apparent vertical piezoresponse is prone to parasitic electrostatic effects, shear piezoelectric activity is strongly affected by doping. Undoped α-glycine shows no shear piezoelectric response at all. The shear response of the L-alanine doped crystals is much larger than those of the L-threonine doped crystals and co-doped crystals. These observations are rationalized in terms of host–guest molecule interactions.

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