Maxwell relation, giant (negative) electrocaloric effect, and polarization hysteresis

2021 ◽  
Vol 118 (12) ◽  
pp. 122904
Author(s):  
Xin Chen ◽  
Siqi Li ◽  
Xiaodong Jian ◽  
Yusra Hambal ◽  
Sheng-Guo Lu ◽  
...  
Keyword(s):  
Electrocaloric Effect ◽  
Maxwell Relation

Estimate of Thermodynamic Indirect Measurement on the Electrocaloric Effect

2011 ◽  
Vol 492 ◽  
pp. 164-167 ◽  
Author(s):  
Kai Ding ◽  
Yang Bai ◽  
Xi Han ◽  
Wen Jie Zhang ◽  
Li Jie Qiao
Keyword(s):  
Ferroelectric Material ◽  
Indirect Measurement ◽  
Temperature Resolution ◽  
Electrocaloric Effect ◽  
Accuracy Measurement ◽  
Maxwell Relation ◽  
True Value ◽  
Testing Frequency ◽  
Direct Measurements ◽  
Different Temperatures

The thermodynamics indirect measurement based on Maxwell relation is one of the most popular methods for the studies on electrocaloric effect of ferroelectric material, including bulk ceramics, single crystals and thin films.However,recent reports indicated that the results obtained through this method did not agree with those from the direct measurements in many cases, such as nearTcor under high electric field. This paper discussed the applicability of thermodynamics indirect measurement and analyzed the reason why its calculated result may be different from the true value of electrocaloric effect. Because the thermodynamics indirect characterization depends on the measurement of polarization at different temperatures, the testing frequency ofP-Eloops, leakage current of sample and temperature resolution of measurement play the important roles in the accuracy measurement of electrocaloric effect.

scholarly journals Enhanced Electrocaloric Effect in 0.73Pb(Mg1/3Nb2/3)O3-0.27PbTiO3 Single Crystals via Direct Measurement

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 451 ◽  
Author(s):  
Biao Lu ◽  
Xiaodong Jian ◽  
Xiongwei Lin ◽  
Yingbang Yao ◽  
Tao Tao ◽  
...  
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Indirect Method ◽  
Phenomenological Theory ◽  
Measured Temperature ◽  
Electrocaloric Effect ◽  
Temperature Changes ◽  
Temperature Range ◽  
Maxwell Relation ◽  
Adiabatic Temperature Change

Electrocaloric properties of [110] and [111] oriented 0.73Pb(Mg1/3Nb2/3)O3-0.27PbTiO3 single crystals were studied in the temperature range of 293–423 K. The Maxwell relations and the Landau–Ginsburg–Devonshire (LGD) phenomenological theory were employed as the indirect method to calculate the electrocaloric properties, while a high-resolution calorimeter was used to measure the adiabatic temperature change of the electrocaloric effect (ECE) directly. The results indicate that the directly measured temperature changes of ΔT > 2.5 K at room temperature were procured when the applied electric field was reversed from 1 MV/m to −1 MV/m, which are larger than those deduced pursuant to the Maxwell relation, and even larger than those calculated using the LGD theory in the temperature range of 293–~380 K.

Comment on “Giant pyroelectric energy harvesting and a negative electrocaloric effect in multilayered nanostructures” by G. Vats, A. Kumar, N. Ortega, C. R. Bowen and R. S. Katiyar, Energy Environ. Sci., 2016, 9, 1335

2021 ◽  
Author(s):  
Xin Chen ◽  
Vladimir Shvartsman ◽  
Doru C. Lupascu ◽  
Q. M. Zhang
Keyword(s):  
Energy Harvesting ◽  
Ferroelectric Phase ◽  
Hysteresis Loops ◽  
Electrocaloric Effect ◽  
Maxwell Relation ◽  
Multilayered Nanostructures ◽  
Energy Environ

In the ferroelectric phase, the change of polarization with temperature from partially switched polarization hysteresis loops has no relation with the electrocaloric effect (ECE) and hence cannot be used in Maxwell relation to deducing ECE.

scholarly journals Energy Storage Capacity and Electrocaloric Effect on Sn Modified Barium Titanium Oxide (BaTi0.8Sn0.2O3)

2021 ◽  
Author(s):  
JYOTIREKHA MALLICK ◽  
Lagen Kumar Pradhan ◽  
Murli Kumar Manglam ◽  
Manoranjan Kar
Keyword(s):  
Energy Storage ◽  
Temperature Variation ◽  
Titanium Oxide ◽  
Solid State Reaction Method ◽  
Electrocaloric Effect ◽  
Barium Titanium Oxide ◽  
Maxwell Relation ◽  
Storage Behavior ◽  
Energy Storage Efficiency ◽  
Barium Titanium

Abstract Modified Barium Titanium Oxide ( BaTi 0.8 Sn 0.2 O 3 ) was prepared by using the solid-state reaction method. The crystal structure, energy storage behavior, and electrocaloric properties were studied. The phase purity and structural analysis were investigated using the X-ray diffraction technique and the Rietveld refinement of XRD pattern. The microstructure of the sample was recorded by using the Field Emission Scanning Electron Microscopy (FESEM). The temperature variation dielectric property shows that the ceramic exhibits diffuse phase transition behaviour. The ferroelectric nature in BaTi 0.8 Sn 0.2 O 3 has been depicted from P-E loops analysis. The energy storage behaviour and electrocaloric properties were estimated from the temperature variation P-E loops at 40kV/cm. The electrocaloric effect was studied by an indirect method using Maxwell relation, and the electrocaloric value has been estimated to with 94% of energy storage efficiency.

scholarly journals Large electrocaloric effect obtained in Ba(SnxTi1−x)O3 lead-free ceramics using direct and indirect measurements

2018 ◽  
Vol 08 (05) ◽  
pp. 1850038 ◽  
Author(s):  
Jiang Li ◽  
Dan-Dan Li ◽  
Biao Lu ◽  
Ying-Bang Yao ◽  
Tao Tao ◽  
...  
Keyword(s):  
Curie Temperature ◽  
High Temperatures ◽  
Broad Peak ◽  
Lead Free ◽  
Electrocaloric Effect ◽  
Indirect Measurements ◽  
Temperature Range ◽  
Maxwell Relation ◽  
Lead Free Ceramics ◽  
Measurement Results

The electrocaloric effect (ECE) in lead-free BaSnxTi[Formula: see text]O3 (BSnT, [Formula: see text], 0.10 and 0.15) ceramics were investigated using a direct ECE measurement. Results indicate that the maximum ECE occurs near the Curie temperature and it slightly shifts towards high temperatures. The directly measured ECE is larger than that calculated using the Maxwell relation and P-E loops. A maximum electrocaloric efficiency [Formula: see text][Formula: see text]KmV[Formula: see text] was procured for the composition with [Formula: see text] at [Formula: see text][Formula: see text]K. And it also shows a broad peak in the temperature range of 250–320[Formula: see text]K.

The Electrocaloric Effect of BaTiO3 Ceramics Using Hydrothermal Synthesized Nano-Sized Starting Powders

2012 ◽  
Vol 624 ◽  
pp. 138-141
Author(s):  
Xi Han ◽  
Yang Bai ◽  
Li Jie Qiao
Keyword(s):  
Phase Transition ◽  
Curie Point ◽  
Applied Field ◽  
Hysteresis Loops ◽  
Electrocaloric Effect ◽  
Maxwell Relation ◽  
Adiabatic Temperature Change ◽  
Good Consistency ◽  
Titanate Ceramics ◽  
Dsc Curves

The electrocaloric effect (ECE) of barium titanate ceramics with hydrothermal synthesized nano-sized starting powders was investigated. The Curie point and latent heat of the phase transition were characterized by a differential scanning calorimeter (DSC). The P-E hysteresis loops were measured in the temperature range from 30-160oC and ECE adiabatic temperature change was obtained according to the Maxwell relation. A double hysteresis loop is observed at the temperature slightly above the Curie point, which indicates a good consistency of phase transition similar to single crystal. It is also proved by the sharp endothermic peak of phase transition in DSC curves. It exhibits a high ECE of ΔTmax=1.3K under a low applied field of 10kV/cm, which is much higher than that of the sample using micron-sized starting powders.

Adjustable negative electrocaloric effect in Pb1+xZrO3 thin films

2021 ◽  
Author(s):  
Yi Ye ◽  
Fengzhen Huang ◽  
Lin Lei ◽  
Lin Liu ◽  
Shuo Yan ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrocaloric Effect

scholarly journals A unified perturbative approach to electrocaloric effects

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Mónica Graf ◽  
Jorge Íñiguez
Keyword(s):  
External Field ◽  
Taylor Series ◽  
Physical Interpretation ◽  
Applied Field ◽  
Atomistic Simulations ◽  
Small Field ◽  
Electrocaloric Effect ◽  
Perturbative Approach ◽  
Similarities And Differences ◽  
Straightforward Interpretation

AbstractThe electrocaloric effect, that is, the temperature change experienced by an insulator upon application of an electric field, offers promising ecofriendly alternatives to refrigeration. However, the theoretical treatments of this response are mostly case specific and lack a unified picture revealing the similarities and differences among the various known effects. Here, we show that the electrocaloric effect lends itself to a straightforward interpretation when expressed as a Taylor series in the external field. Our formalism explains in a unified and simple way the most notable small-field effects reported in the literature, namely the so-called normal and inverse electrocaloric responses, corresponding to an increase or decrease of temperature under applied field, as usually found in ferroelectrics or antiferroelectrics, respectively. This helps us to clarify their physical interpretation. We then discuss in detail atomistic simulations for the prototype ferroelectric PbTiO3, explicitly evaluating subtle predictions of the theory, such as the occurrence of competing contributions to the electrocaloric response.

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