Internal Stress Generation During Switching of Ferroelectrics

2005 ◽  
Vol 881 ◽  
Author(s):  
Anja Haug ◽  
Patrick R. Onck ◽  
Erik Van der Giessen
Keyword(s):  
Electric Field ◽  
Internal Stress ◽  
Hysteresis Loops ◽  
Ferroelectric Materials ◽  
Stress Generation ◽  
Internal Stresses ◽  
Two Dimensional ◽  
Micromechanics Model ◽  
Field Distributions ◽  
Multigrain Model

AbstractProgressive switching of grains in ferroelectric materials leads to internal stresses, which may give rise to degradation of the material or even fracture. Here we propose a two-dimensional multigrain model for ferroelectric polycrystal. The numerical computations employ the nonlinear micromechanics model of Huber et al. [1] for each grain. Results for the macroscopic response, butterfly and hysteresis loops, as well as internal stress and electric field distributions are presented.

scholarly journals Investigation of the dielectric fatigue on the example of lead titanate films PbTiO3

2021 ◽  
Vol 2086 (1) ◽  
pp. 012179
Author(s):  
A V Fimin ◽  
E A Pecherskaya ◽  
O A Timokhina ◽  
V S Aleksandrov ◽  
A V Volik ◽  
...  
Keyword(s):  
Thin Films ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Lead Titanate ◽  
Piecewise Linear ◽  
Hysteresis Loops ◽  
Ferroelectric Materials ◽  
Piecewise Linear Approximation ◽  
Residual Polarization

Abstract The phenomenon of dielectric fatigue of active dielectrics, which consists in a decrease in the residual polarization depending on the number of switching cycles, is researched. A model of the dependence of the residual polarization of ferroelectric materials on the number of switching cycles is proposed. The model is based on piecewise - linear approximation of the results of measurements of the hysteresis loops of thin films PbTiO3 at a temperature T = 470 (°C), the electric field strength E = 100 (kV/cm). The developed model was used in the development of a technique for studying dielectric fatigue, depending on different modes of material switching.

Hysteretic Dynamics of Ferroelectric Materials Under Electro-Mechanical Loadings

2008 ◽  
Author(s):  
Linxiang Wang
Keyword(s):  
Electric Field ◽  
Phase Transformations ◽  
Landau Theory ◽  
Hysteresis Loops ◽  
Ferroelectric Materials ◽  
Differential Model ◽  
Mechanical Coupling ◽  
First Order ◽  
Bias Stress ◽  
First Order Phase

In the current paper, the hysteretic dynamics of ferroelectric materials under combined electro-mechanical loadings is investigated using a macroscopic differential model. The model is constructed on the basis of the Landau theory of the first order phase transformations. Hysteresis loops in the electric field and the butterfly-shaped behaviors in the electro-mechanical coupling are modeled as a consequence of polarizations and orientation switchings, together with nonlinear electro-mechanical coupling effects. The effects of bias stress on the orientation switchings are investigated numerically. Comparison of the model results with its experimental counterparts is presented, capability of the model is approved.

Recent Progress in Ferroelectric Random Access Memory Technology

2007 ◽  
Vol 997 ◽  
Author(s):  
Hiroshi Ishiwara ◽  
Hiroshi Ishiwara
Keyword(s):  
Electric Field ◽  
Leakage Current ◽  
Retention Time ◽  
Cell Structure ◽  
Random Access ◽  
Hysteresis Loops ◽  
Ferroelectric Materials ◽  
Buffer Layers ◽  
Data Retention ◽  
Gate Structure

AbstractIn this paper, ferroelectric materials suitable for realizing high-density 1T1C-type (capacitor-type) FeRAM are first reviewed. It is found in BiFeO3(BFO) films formed by chemical solution deposition that leakage current density at a low electric field increases by substitution of Mn and Cr atoms for Fe atoms. But, it is also found that the breakdown characteristic is much improved by substitution of these atoms. Because of the better breakdown characteristic, the leakage current densities in the 3 and 5% Mn-substituted films are lower than that in an undoped BFO film at an applied electric field of 1MV/cm at room temperature, and thus well saturated hysteresis loops in P-E (polarization vs. electric field) characteristics are observed in these films.Next, recent technological progress in transistor-type FeRAM, in which data are stored in a single ferroelectric-gate FET(field effect transistor), is discussed. It is demonstrated that the data retention time of ferroelectric-gate FETs is much improved by use of HfO2-based buffer layers which are inserted between the ferroelectric film and Si substrate for preventing interdiffusion of constituent elements. Particular attention is paid to FETs with a Pt/SrBi2Ta2O9/HfO2/Si gate structure, in which the data retention time longer than 30 days has been attained. Finally, the cell structure and operation principle of 1T (one transistor)-type FeRAM are discussed.

Biaxial strain, electric field and interlayer distance-tailored electronic structure and magnetic properties of two-dimensional g-C3N4/Li-adsorbed Cr2Ge2Te6 van der Waals heterostructures

2021 ◽  
Vol 23 (10) ◽  
pp. 6171-6181
Author(s):  
Yaoqi Gao ◽  
Baozeng Zhou ◽  
Xiaocha Wang
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Electric Field ◽  
Van Der Waals ◽  
Interlayer Distance ◽  
Two Dimensional ◽  
Biaxial Strain ◽  
Van Der Waals Heterostructures

It is found that the biaxial strain, electric field and interlayer distance can effectively modulate the electronic structure and magnetic properties of two-dimensional van der Waals heterostructures.

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