scholarly journals Piezoelectric Nonlinearity and Hysteresis Arising from Dynamics of Electrically Conducting Domain Walls

2021 ◽  
Author(s):  
Tadej Rojac

Macroscopic nonlinearity and hysteresis observed in the piezoelectric and dielectric responses of ferroelectric materials to external stimuli are commonly attributed to localized displacements of domain walls (DWs). The link between the macroscopic response and microscopic DW dynamics is provided by the well-known Rayleigh relations, extensively used to quantify the electrical and electromechanical behavior of ferroelectric ceramics and thin films under subswitching conditions. In this chapter, I will present an intriguing case where DWs exhibit enhanced electrical conductivity with respect to the bulk conductivity. By combining experimental data and modeling, it will be shown that the local conductivity, related to accumulation of charged points defect at DWs, does not only affect DW dynamics through DW-defect pinning interactions, as we may expect, but goes beyond it by affecting the macroscopic nonlinearity and hysteresis in a more complex manner. The major characteristics and implications of the underlying nonlinear Maxwell-Wagner piezoelectric relaxation, triggered by the presence and dynamics of conducting DWs, will be presented, reviewed and discussed in the framework of systematic multiscale analyses on BiFeO3 ceramics. The result may have implications in the development of promising BiFeO3-based compositions for high-temperature piezoelectric applications.

Author(s):  
Wenwu Cao

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,


2002 ◽  
Vol 17 (6) ◽  
pp. 1376-1384 ◽  
Author(s):  
Marlyse Demartin Maeder ◽  
Dragan Damjanovic ◽  
Cyril Voisard ◽  
Nava Setter

The dynamic piezoelectric response of SrBi4Ti4O15 ceramics with Aurivillius structure was investigated at high alternating stress, low frequencies (0.01 to 100 Hz), and temperatures from 20 to 200 °C. The piezoelectric nonlinearity, observed only at high pressures (>10 MPa) and elevated temperatures (>150 °C), is interpreted in terms of contributions from non-180° domain walls. At weak fields, the frequency dependence of the longitudinal piezoelectric coefficient was explained in terms of Maxwell–Wagner piezoelectric relaxation. The Maxwell–Wagner units are identified as colonies that consist of highly anisotropic grains which sinter together, and whose distribution in the ceramic is strongly dependent on sintering conditions.


2017 ◽  
Vol 56 (10S) ◽  
pp. 10PA01 ◽  
Author(s):  
Tadej Rojac ◽  
Dragan Damjanovic

2019 ◽  
Vol 945 ◽  
pp. 771-775 ◽  
Author(s):  
V.P. Panaetov ◽  
Denis B. Solovev

Ferromagnetic film can be a matrix for recording information with the help of magnetic moments of electrons. The study of the processes of changing the magnetic structure in an electron-transmission microscope makes it possible to investigate micro magnetic phenomena. In this paper, we investigate the interaction between the vertices of neighboring regions. It is shown how the magnetic structure of the vertices of the domains changes as they approach each other with the help of an increasing constant magnetic field applied along the axis of easy magnetization. The distance was measured between the vertices of the domains. The schemes of distribution of the magnetization vectors between interacting vertices are shown. These schemes are made from experimental images of the magnetic structure. The distances between domain vertices and domain walls were compared on the basis of experimental data. The film thickness is 50 nm; the structure is Ni0.83-Fe0.17. The films were obtained by the method proposed by us. From the experimental results it follows that the interaction of the domain walls is observed at a distance of 20 microns and the interaction of the domain vertices is manifested at a distance of 100 μm.


2007 ◽  
Vol 1034 ◽  
Author(s):  
Marek Pasciak ◽  
Stefano Leoni

AbstractA design approach to ferroelectric materials critically depends on an accurate description of the microscopic features associated with paraelectric-to-ferroelectric phase transitions. The fine structures of domains, domain walls, and domain boundary dynamics as well as a precise understanding of local atomic displacements can be accessed using adequate potential models based on ab initio calculations and advanced molecular dynamics simulations. For BaTiO3 a complex scenario of microscopic domains in the paraelectric (cubic) phase and in the ferroelectric (tetragonal) phase is obtained. Therein, the static and dynamic role of domain/antidomain features, as well as their dependence on Ti displacements around the <111> manifold is clearly emerging.


2008 ◽  
Vol 606 ◽  
pp. 119-134 ◽  
Author(s):  
Sarah Leach ◽  
R. Edwin Garcia

In the last ten years of ongoing research in the modeling of polycrystalline ferroelectric ceramics a myriad of analytical and numerical implementations have emerged to predict and support the engineering of ferroelectrics in both its single-crystal and polycrystalline forms. Traditional atomistic approaches capture the intrinsic behaviors, and have led to great improvements in the chemistries of these systems. Similarly, macroscopic engineering approaches have focused on the development of phenomenological descriptions that capture the empirical static and time-independent behavior. At the interface of these two apparently divorced approaches, thermodynamic-based microstructural evolution descriptions inspired in phase field models have risen as the necessary link between the atomic and macroscopic levels. This new and emerging methodology starts from the predicted behaviors given by their atomic counter-parts, and resolves the effects of grain boundaries, and de-convolves the grain-grain mesoscopic interactions. Much of the future of ferroelectrics lies in the delivery of improved chemistries and microstructures, and on bridging the understanding currently existing atomistic and continuum descriptions. Overall, it is expected that current and emerging technological challenges will be the driving force to minimize ferroelectric fatigue and realize lead-free materials with performances close to currently existing (lead containing) ones. Moreover, it is expected that while an accurate understanding of the intrinsic properties of materials are key to define improved ferroelectric solids, it will be the detailed understanding of the extrinsic response of ferroelectric materials, in both bulk and thin film form, that will take these materials to reach the highest performances possible.


2010 ◽  
Vol 96 (22) ◽  
pp. 221905 ◽  
Author(s):  
Ning Lu ◽  
Rong Yu ◽  
Zhiying Cheng ◽  
Yejing Dai ◽  
Xiaowen Zhang ◽  
...  

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