Dynamical Nonlinearities in Piezoelectric Materials

2007 ◽  
Vol 1034 ◽  
Author(s):  
Eira Seppälä ◽  
Virpi Korpelainen ◽  
Kari Ojasalo ◽  
Matti Sarjala ◽  
Mikko Alava ◽  
...  

AbstractDynamical nonlinearities in piezoelectric materials have been investigated over different time and frequency scales using four different methods; measurements of displacement and electric polarization of bulk material, measurements of nanometer scale surface structure of the material by an atomic force microscope (AFM), and numerical modelling of ferroelectric materials with quenched randomness. Laser vibrometer measurements of the deformations of piezoelectric materials, d31 type PZT and PMN-PT sheets, have been done under sinusoidal voltage loading with different frequencies. This yields information about the dynamical hysteresis behavior, such as the area of the hysteresis loops as a function of the applied frequency f and voltage amplitude. Similarly the hysteresis loops have been measured for the electric polarization of the same samples. Relaxation behaviors of the same materials have been measured by an AFM. Topography of the piezo sheets was measured after applied DC voltage, indicating slow collective changes in the polarization close and at the sample surface. To investigate the time-dependent hysteresis, we have studied numerically a Ginzburg-Landau-Devonshire (GLD) model for ferroelectric materials including dilution type quenched randomness. Quantities studied include the area of the hysteresis loop, of the polarization in the material, and the coercive electric field Ec as a function of the frequency f, both as a function of the disorder strength.

2008 ◽  
Vol 8 (6) ◽  
pp. 2912-2922
Author(s):  
N. Iturriza ◽  
L. Fernández ◽  
A. Chizhik ◽  
G. Vara ◽  
A. R. Pierna ◽  
...  

Different kinds of magnetic anisotropies have been induced during the nanocrystallization process of Co- and Ni-rich amorphous ferromagnetic (Finemet) ribbons by the application of a constant stress or an axial magnetic field during the annealing process. Magnetization measurements have evidenced the presence od macroscopic anisotropy in the treated samples. The main goal of this work has been, after a careful DSC study, the structural analysis of the treated ribbons using X-ray Diffraction and Atomic Force Microscopy (AFM), detecting substantial differences in the crystallization state and grain size of the samples depending on the thermal treatment that was carried out. Moreover, AFM measurements revealed in all the treated samples a strong nanocrystallisation of the surface without evidences of amorphous matrix, which contrast with XRD measurements that have shown a high content of amorphous phase in the bulk of the ribbons. Magneto-optical Kerr effect measurements have been performed with the aim to elucidate the complex magnetic behaviour that is expected for the surface of the ribbons, measuring surface hysteresis loops that showed much higher coercive field values than that obtained in the bulk material.


2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060003
Author(s):  
Inna Andryushina ◽  
Anatoliy Pavlenko ◽  
Sergey Zinchenko ◽  
Konstantin Andryushin ◽  
Lidiya Shilkina ◽  
...  

This paper presents the results of studies of the structure, microstructure, dependences of the piezoelectric properties on the electric field (dielectric hysteresis loops, reversible nonlinearity, deformation characteristics) and dielectric properties of the ceramic material PCR-13 (based on the PZT system) in the temperature range 300–900[Formula: see text]K and frequencies of an alternating electric field ([Formula: see text]) Hz. The character of the obtained dependences made it possible to attribute PCR-13 to ferro-hard materials. Using the HF cathodic sputtering method, PCR-13 thin films were fabricated on Si (001) substrates. It is shown that they are polycrystalline textured, while in comparison with bulk material, the film contains tensile stresses of the unit cell in the plane of the substrate and compresses in the perpendicular direction with the value [Formula: see text]. The capacitance-voltage characteristics of the Al/PCR-13/Si/Al heterostructure were studied. The reasons for the revealed patterns are discussed.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sangmo Kim ◽  
Thi My Huyen Nguyen ◽  
Rui He ◽  
Chung Wung Bark

AbstractPiezoelectric nanogenerators (PNGs) have been studied as renewable energy sources. PNGs consisting of organic piezoelectric materials such as poly(vinylidene fluoride) (PVDF) containing oxide complex powder have attracted much attention for their stretchable and high-performance energy conversion. In this study, we prepared a PNG combined with PVDF and lanthanum-modified bismuth titanate (Bi4−XLaXTi3O12, BLT) ceramics as representative ferroelectric materials. The inserted BLT powder was treated by high-speed ball milling and its particle size reduced to the nanoscale. We also investigated the effect of particle size on the energy-harvesting performance of PNG without polling. As a result, nano-sized powder has a much larger surface area than micro-sized powder and is uniformly distributed inside the PNG. Moreover, nano-sized powder-mixed PNG generated higher power energy (> 4 times) than the PNG inserted micro-sized powder.


2019 ◽  
Author(s):  
Jose J Plata ◽  
Javier Amaya Suárez ◽  
Santiago Cuesta-López ◽  
Antonio Marquez ◽  
Javier Fdez. Sanz

<div> <div> <div> <p>Conventional solar cell efficiency is usually limited by the Shockley-Queisser limit. This is not the case, however, for ferroelectric materials, which present a spontaneous electric polarization that is responsible for their bulk photovoltaic effect. Even so, most ferroelectric oxides exhibit large band gaps, reducing the amount of solar energy that can be harvested. In this work, a high-throughput approach to tune the electronic properties of thin-film ferroelectric oxides is presented. Materials databases were systematically used to find substrates for the epitaxial growth of KNbO3 thin-films, using topological and stability filters. Interface models were built and their electronic and optical properties were predicted. Strain and substrate-thin-film band interaction effects were examined in detail, in order to understand the interaction between both materials. We found substrates that significantly reduce the KNbO3 band gap, maintain KNbO3 polarization, and potentially present the right band alignment, favoring the electron injection in the substrate/electrode. This methodology can be easily applied to other ferroelectric oxides, optimizing their band gaps and accelerating the development of new ferroelectric-based solar cells. </p> </div> </div> </div>


2014 ◽  
Vol 809-810 ◽  
pp. 17-25
Author(s):  
Ming Chao Che ◽  
Jie Chen

Barium titanate (BaTiO3) used a strong dielectric materials, piezoelectric materials and ferroelectric materials, which is a kind of important electronic ceramic materials. With the miniaturization of electronic components, miniaturization, thin layer, nanosized barium titanate powder become an inevitable developing trend of barium titanate dielectric ceramics material. Some recent new progress for synthesis of barium titanate at home and abroad are summarized, the commentaries are made on the preparation process about advantages or disadvantages. Meanwhile, the analysis is made on the developing trend. Supercritical fluid extraction method have simple process, high extraction efficiency, no organic solvent residual, products of good quality, no environmental pollution, and so on. Research of BaTiO3nanopower may become an important direction of the field in the future.


2005 ◽  
Vol 881 ◽  
Author(s):  
Alexander York ◽  
Stefan Seelecke

AbstractThe rate-dependence of piezoelectric materials resulting from the kinetics of domain switching is an important factor that needs to be included in realistic modeling attempts. This paper provides a systematic study of the rate-dependent hysteresis behavior of a commercially available PZT stack actuator. Experiments covering full as well as minor loops are conducted at different loading rates with polarization and strain recorded. In addition, the creep behavior at different constant levels of the electric field is observed. This provides evidence of kinetics being characterized by strongly varying relaxation times that can be associated with different switching mechanisms.


2020 ◽  
Vol 312 ◽  
pp. 235-243
Author(s):  
Lev Aleksandrovich Ivanov ◽  
Tatiana P. Kaminskaya ◽  
Irina Semenovna Tereshina ◽  
Vladislav Davydov ◽  
Vladimir V. Popov ◽  
...  

Magnetic force microscopy (MFM) and magnetometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to study the magnetic and structural properties of the (Nd,Pr)-Fe–B and (Nd,Ho)-(Fe,Co)-B alloys. The alloys are synthesized using an arc or induction furnaces. The nanocrystalline state of the (Nd,Ho)-(Fe,Co)-B alloys is reached by two techniques, namely, melt spinning (MS) and severe plastic deformation (SPD). Hydrogenation and multistage treatment of (Nd,Ho)-(Fe,Co)-B alloys, which includes severe plastic deformation of melt-quenched ribbons and subsequent heat treatment, is also used. The surface morphology and domain structure of samples are studied. These pictures are used to interpret the observed magnetic hysteresis loops of the samples. It was found that multistage treatment allows one to obtain samples with higher values of coercivity due to the formation of a special microstructure with oval grain (the aspect ratio equal to ∼ 3).


1999 ◽  
Vol 5 (S2) ◽  
pp. 962-963
Author(s):  
M. VanLandingham ◽  
X. Gu ◽  
D. Raghavan ◽  
T. Nguyen

Recent advances have been made on two fronts regarding the capability of the atomic force microscope (AFM) to characterize the mechanical response of polymers. Phase imaging with the AFM has emerged as a powerful technique, providing contrast enhancement of topographic features in some cases and, in other cases, revealing heterogeneities in the polymer microstructure that are not apparent from the topographic image. The enhanced contrast provided by phase images often allows for identification of different material constituents. However, while the phase changes of the oscillating probe are associated with energy dissipation between the probe tip and the sample surface, the relationship between this energy dissipation and the sample properties is not well understood.As the popularity of phase imaging has grown, the capability of the AFM to measure nanoscale indentation response of polymers has also been explored. Both techniques are ideal for the evaluation of multi-phase and multi-component polymer systems.


2010 ◽  
Vol 03 (01) ◽  
pp. 79-81 ◽  
Author(s):  
BAOJIN CHU ◽  
WENYI ZHU ◽  
NAN LI ◽  
L. ERIC CROSS

Flexoelectricity describes the physical phenomenon of the generation of electric polarization from mechanical strain gradient in solid insulators. In common dielectric materials, the flexoelectric coefficient is trivially small ~10-10 C/m. In Ba(Sr,Ti)O 3 (BST) ceramics, flexoelectric coefficient up to 10-4 C/m was observed. Such high coefficient makes it possible to design high piezoelectric response flexoelectric composites. In this letter, we will demonstrate that the newly designed flexoelectric composites could have piezoelectric properties better than conventional piezoelectric materials.


2001 ◽  
Vol 688 ◽  
Author(s):  
J. Rodríguez Contreras ◽  
J. Schubert ◽  
U. Poppe ◽  
O. Trithaveesak ◽  
K. Szot ◽  
...  

AbstractWe have prepared single crystalline epitaxial PbZr0.52Ti0.48O3 (PZT) and BaTiO3 (BTO) thin films on single crystalline epitaxial SrRuO3 (SRO) thin films grown on SrTiO3 (100) (STO) substrates. PZT and SRO thin films were grown using high-pressure on-axis sputtering and BTO using pulsed laser deposition (PLD). The film thickness ranged between 12 to 165 nm. Their excellent structural properties, surface smoothness and interface sharpness were demonstrated by X-Ray Diffraction measurements (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Rutherford Backscattering Spectrometry and Channeling measurements (RBS/C) were used to analyze stoichiometry and crystalline quality. Ferroelectric hysteresis loops were obtained for all films of a thickness down to 12 nm showing a decrease in the remanent polarization Pr and an increase in the coercive field Ec towards thinner film thicknesses. Furthermore we have prepared tunneling junctions with a PZT or BTO barrier thickness of 3-6 nm. Reproducible bi-stable I-V-curves and bias dependence of the conductance were obtained suggesting an influence of the ferroelectric properties of the barrier material on the tunnel current.


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