Browse
Submit Data
Databases
API
Help

Dataset Information

34 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Vibration induced refrigeration using ferroelectric materials.

ABSTRACT: This article aims to propose a cantilever based cooling device employing non-axis symmetric placement of bulk ferroelectric patches. Ambient mechanical vibrations produce large stresses in cantilevers resulting in elastocaloric effect associated with ferroelectrics. Further, design allows cascading of several cantilevers to achieve large cooling response. A finite element analysis of the system was performed using material properties of bulk 0.50Ba(Zr_0.2Ti_0.8)O₃-0.50(Ba_0.7Ca_0.3)TiO₃. An individual element could produce a peak elastocaloric effect of 0.02?K (324?K); whereas the proposed system could achieve a temperature drop of 0.2?K within 50?seconds (10 elements, 1.5?Hz). Furthermore, net cooling can be further improved about ~2?K (using 10 cantilevers) for a starting temperature of 358?K. This study shows that elastocaloric effect in ferroelectric materials is capable of converting waste mechanical vibration into refrigeration effect which is not reported so far.

SUBMITTER: Kumar A

PROVIDER: S-EPMC6408585 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Vibration induced refrigeration using ferroelectric materials.

Kumar Anuruddh A Chauhan Aditya A Patel Satyanarayan S Novak Nikola N Kumar Rajeev R Vaish Rahul R

Scientific reports 20190308 1

This article aims to propose a cantilever based cooling device employing non-axis symmetric placement of bulk ferroelectric patches. Ambient mechanical vibrations produce large stresses in cantilevers resulting in elastocaloric effect associated with ferroelectrics. Further, design allows cascading of several cantilevers to achieve large cooling response. A finite element analysis of the system was performed using material properties of bulk 0.50Ba(Zr0.2Ti0.8)O3- ...[more]

PMID: 30850629

Similar Datasets

Depolarization of multidomain ferroelectric materials.

Project description:Depolarization in ferroelectric materials has been studied since the 1970s, albeit quasi-statically. The dynamics are described by the empirical Merz law, which gives the polarization switching time as a function of electric field, normalized to the so-called activation field. The Merz law has been used for decades; its origin as domain-wall depinning has recently been corroborated by molecular dynamics simulations. Here we experimentally investigate domain-wall depinning by measuring the dynamics of depolarization. We find that the boundary between thermodynamically stable and depolarizing regimes can be described by a single constant, Pr/ε0εferroEc. Among different multidomain ferroelectric materials the values of coercive field, Ec, dielectric constant, εferro, and remanent polarization, Pr, vary by orders of magnitude; the value for Pr/ε0εferroEc however is comparable, about 15. Using this extracted universal value, we show that the depolarization field is similar to the activation field, which corresponds to the transition from creep to domain-wall flow.

| S-EPMC6560217 | biostudies-literature

Role of ferroelectric polarization during growth of highly strained ferroelectric materials.

Project description:In ferroelectric thin films and superlattices, the polarization is intricately linked to crystal structure. Here we show that it can also play an important role in the growth process, influencing growth rates, relaxation mechanisms, electrical properties and domain structures. This is studied by focusing on the properties of BaTiO3 thin films grown on very thin layers of PbTiO3 using x-ray diffraction, piezoforce microscopy, electrical characterization and rapid in-situ x-ray diffraction reciprocal space maps during the growth using synchrotron radiation. Using a simple model we show that the changes in growth are driven by the energy cost for the top material to sustain the polarization imposed upon it by the underlying layer, and these effects may be expected to occur in other multilayer systems where polarization is present during growth. This motivates the concept of polarization engineering as a complementary approach to strain engineering.

| S-EPMC7251112 | biostudies-literature

Ferroelectric translational antiphase boundaries in nonpolar materials.

Project description:Ferroelectric materials are heavily used in electro-mechanics and electronics. Inside the ferroelectric, domain walls separate regions in which the spontaneous polarization is differently oriented. Properties of ferroelectric domain walls can differ from those of the domains themselves, leading to new exploitable phenomena. Even more exciting is that a non-ferroelectric material may have domain boundaries that are ferroelectric. Many materials possess translational antiphase boundaries. Such boundaries could be interesting entities to carry information if they were ferroelectric. Here we show first that antiphase boundaries in antiferroelectrics may possess ferroelectricity. We then identify these boundaries in the classical antiferroelectric lead zirconate and evidence their polarity by electron microscopy using negative spherical-aberration imaging technique. Ab initio modelling confirms the polar bi-stable nature of the walls. Ferroelectric antiphase boundaries could make high-density non-volatile memory; in comparison with the magnetic domain wall memory, they do not require current for operation and are an order of magnitude thinner.

| S-EPMC3941019 | biostudies-literature

High-efficiency magnetic refrigeration using holmium.

Project description:Magnetic refrigeration (MR) is a method of cooling matter using a magnetic field. Traditionally, it has been studied for use in refrigeration near room temperature; however, recently MR research has also focused on a target temperature as low as 20 K for hydrogen liquefaction. Most research to date has employed high magnetic fields (at least 5 T) to obtain a large entropy change, which requires a superconducting magnet and, therefore, incurs a large energy cost. Here we propose an alternative highly efficient cooling technique in which small magnetic field changes, Δμ0H ≤ 0.4 T, can obtain a cooling efficiency of -ΔSM/Δμ0H = 32 J kg-1K-1T-1, which is one order of magnitude higher than what has been achieved using typical magnetocaloric materials. Our method uses holmium, which exhibits a steep magnetization change with varying temperature and magnetic field. The proposed technique can be implemented using permanent magnets, making it a suitable alternative to conventional gas compression-based cooling for hydrogen liquefaction.

| S-EPMC7896054 | biostudies-literature

Ferroelectric switching in ferroelastic materials with rough surfaces.

Project description:Electric switching of non-polar bulk crystals is shown to occur when domain walls are polar in ferroelastic materials and when rough surfaces with steps on an atomic scale promote domain switching. All domains emerging from surface nuclei possess polar domain walls. The progression of domains is then driven by the interaction of the electric field with the polarity of domain boundaries. In contrast, smooth surfaces with higher activation barriers prohibit effective domain nucleation. We demonstrate the existence of an electrically driven ferroelectric hysteresis loop in a non-ferroelectric, ferroelastic bulk material.

| S-EPMC6825142 | biostudies-literature

Molecular Designs for Enhancement of Polarity in Ferroelectric Soft Materials.

Project description:The racemic oxovanadium(IV) salmmen complexes, [VO((rac)-(4-X-salmmen))] (X?=?C12C10C5 (1), C16 (2), and C18 (3); salmmen?=?N,N'-monomethylenebis-salicylideneimine) with "banana shaped" molecular structures were synthesized, and their ferroelectric properties were investigated. These complexes exhibit well-defined hysteresis loops in their viscous phases, moreover, 1 also displays liquid crystal behaviour. We observed a synergetic effect influenced by three structural aspects; the methyl substituents on the ethylene backbone, the banana shaped structure and the square pyramidal metal cores all play an important role in generating the observed ferroelectricity, pointing the way to a useful strategy for the creation of advanced ferroelectric soft materials.

| S-EPMC4645115 | biostudies-literature

The ferroelectric photo ground state of SrTiO3: Cavity materials engineering.

Project description:Optical cavities confine light on a small region in space, which can result in a strong coupling of light with materials inside the cavity. This gives rise to new states where quantum fluctuations of light and matter can alter the properties of the material altogether. Here we demonstrate, based on first-principles calculations, that such light-matter coupling induces a change of the collective phase from quantum paraelectric to ferroelectric in the [Formula: see text] ground state, which has thus far only been achieved in out-of-equilibrium strongly excited conditions [X. Li et al., Science 364, 1079-1082 (2019) and T. F. Nova, A. S. Disa, M. Fechner, A. Cavalleri, Science 364, 1075-1079 (2019)]. This is a light-matter hybrid ground state which can only exist because of the coupling to the vacuum fluctuations of light, a photo ground state The phase transition is accompanied by changes in the crystal structure, showing that fundamental ground state properties of materials can be controlled via strong light-matter coupling. Such a control of quantum states enables the tailoring of materials properties or even the design of novel materials purely by exposing them to confined light.

| S-EPMC8346861 | biostudies-literature

Ferroelectric self-assembled molecular materials showing both rectifying and switchable conductivity.

Project description:Advanced molecular materials that combine two or more physical properties are typically constructed by combining different molecules, each being responsible for one of the properties required. Ideally, single molecules could take care of this combined functionality, provided they are self-assembled correctly and endowed with different functional subunits whose strong electronic coupling may lead to the emergence of unprecedented and exciting properties. We present a class of disc-like semiconducting organic molecules that are functionalized with strong dipolar side groups. Supramolecular organization of these materials provides long-range polar order that supports collective ferroelectric behavior of the side groups as well as charge transport through the stacked semiconducting cores. The ferroelectric polarization in these supramolecular polymers is found to couple to the charge transport and leads to a bulk conductivity that is both switchable and rectifying. An intuitive model is developed and found to quantitatively reproduce the experimental observations. In a larger perspective, these results highlight the possibility of modulating material properties using the large electric fields associated with ferroelectric polarization.

| S-EPMC5621973 | biostudies-literature

Optically Induced Ferroelectric Polarization Switching in a Molecular Ferroelectric with Reversible Photoisomerization.

Project description:Ferroelectrics usually exhibit temperature-triggered structural changes, which play crucial roles in controlling their physical properties. However, although light is very striking as a non-contact, non-destructive, and remotely controlled external stimuli, ferroelectric crystals with light-triggered structural changes are very rare, which holds promise for optical control of ferroelectric properties. Here, an organic molecular ferroelectric, N-salicylidene-2,3,4,5,6-pentafluoroaniline (SA-PFA), which shows light-triggered structural change of reversible photoisomerization between cis-enol and trans-keto configuration is reported. SA-PFA presents clear ferroelectricity with the saturate polarization of 0.84 μC cm-2 , larger than those of some typical organic ferroelectrics with thermodynamically structural changes. Benefit from the reversible photoisomerization, the dielectric real part of SA-PFA can be reversibly switched by light. More strikingly, the photoisomerization enables SA-PFA to show reversible optically induced ferroelectric polarization switching. Such intriguing behaviors make SPFA a potential candidate for application in next-generation photo-controlled ferroelectric devices. This work sheds light on further exploration of more excellent molecular ferroelectrics with light-triggered structural changes for optical control of ferroelectric properties.

| S-EPMC8693059 | biostudies-literature

Defect Engineering of Hafnia-Based Ferroelectric Materials for High-Endurance Memory Applications.

Project description:Zirconium-doped hafnium oxide (HfZrOx) is one of the promising ferroelectric materials for next-generation memory applications. To realize high-performance HfZrOx for next-generation memory applications, the formation of defects in HfZrOx, including oxygen vacancies and interstitials, needs to be optimized, as it can affect the polarization and endurance characteristics of HfZrOx. In this study, we investigated the effects of ozone exposure time during the atomic layer deposition (ALD) process on the polarization and endurance characteristics of 16-nm-thick HfZrOx. HfZrOx films showed different polarization and endurance characteristics depending on the ozone exposure time. HfZrOx deposited using the ozone exposure time of 1 s showed small polarization and large defect concentration. The increase of the ozone exposure time to 2.5 s could reduce the defect concentration and improve the polarization characteristics of HfZrOx. When the ozone exposure time further increased to 4 s, a reduction of polarization was observed in HfZrOx due to the formation of oxygen interstitials and non-ferroelectric monoclinic phases. HfZrOx, with an ozone exposure time of 2.5 s, exhibited the most stable endurance characteristics because of the low initial defect concentration in HfZrOx, which was confirmed by the leakage current analysis. This study shows that the ozone exposure time of ALD needs to be controlled to optimize the formation of defects in HfZrOx films for the improvement of polarization and endurance characteristics.

| S-EPMC10210041 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data