Study of electrocaloric effect in lead-free 0.9K0.5Na0.5NbO3–0.1CaZrO3 solid solution ceramics

Kumar, Sanjeev; Singh, Satyendra

doi:10.1007/s10854-019-01654-w

Cited by 11 publications

(6 citation statements)

References 35 publications

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“…The ΔT value is almost doubled when the external applied electric field elevated from 40 to 65 kV/cm, proving the significant contribution of electric field to ECE performance. ceramics with FF or FP transitions [12,13,14,34,38,39,40,41]. It can be seen that the ΔT values of this work exceed most of the other KNN-based ceramics under the same or higher electric fields, illustrating that the ceramics prepared in this work are hopeful materials for practical refrigeration applications.…”

Section: Resultsmentioning

confidence: 72%

“…Figure 7: (a) Comparison of ΔT values of this work (the red star) and other KNN-based ceramics under different electric fields [12, 13, 14, 34, 38, 39, 40, 41]; (b) Distribution of temperature span of different ΔT values; (c) Comparison of the temperature span of ΔT values among this work and other KNN-based ceramics (at 40 kV/cm)[12,14,40]; Out-of-plane PFM amplitude and phase images of (d) x = 0.11, (e) x = 0.13, and (f) x = 0.15 ceramics.…”

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confidence: 99%

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Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Zhang

Zheng

Zhao

et al. 2021

Journal of Materials Research

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Lead-free ferroelectric electrocaloric ceramics that could convert electrical energy into heat are the promising candidate for environment-friendly cooling devices. For refrigeration devices, a large temperature change (ΔT ) and good temperature stability are required, which are highly related to the phase structure and the applied electric field. In this work, a diffused ferroelectric-paraelectric (FP) phase transition is formed in (K, Na)NbO 3 (KNN) by using appropriate composition engineering. The relaxor ferroelectrics in this work present both a large ΔT of 1.24 K and a high ΔT/ΔE of 0.19 K mm/kV. In addition, a wide temperature span exceeds 55°C at the high electrocaloric effect (ECE) criterion (ΔT ≥ 0.5 K) could also be observed. This work not only opens a new strategy for obtaining high-performance ceramics for refrigeration devices but also extends the application area of the KNN-based lead-free ferroelectrics from sensors, actuators and energy harvesting to solid-state cooling applications.

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Section: Resultsmentioning

confidence: 72%

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confidence: 99%

Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Zhang

Zheng

Zhao

et al. 2021

Journal of Materials Research

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“…Nowadays, the indirect method of calculating ΔT of ECE is widely used in many piezoelectric materials, such as PZT, 1,5 PMN-PT, 9,24 BT, 2,8,25 and (K 1−x Na x )NbO 3 (KNN). 26,27 ΔT can be calculated using 4 i k j j j y…”

Section: Resultsmentioning

confidence: 99%

“…Based on the Maxwell relationship, (∂ P /∂ T ) E = (∂ S /∂ E ) T , thermal variables and electrical parameters were linked. Nowadays, the indirect method of calculating Δ T of ECE is widely used in many piezoelectric materials, such as PZT, , PMN-PT, , BT, ,, and (K 1– x Na x )NbO 3 (KNN). , Δ T can be calculated using where P , ρ, and C P are the polarization vectors, density, and specific heat capacity, respectively.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Electrocaloric Effect Induced by the Electric-Field-Generated Like-Multiphase Coexistence in Anisotropic KTa_1–xNb_xO₃ Single Crystals

Huang

Tan

Wang

et al. 2022

Crystal Growth & Design

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Electrocaloric (EC) refrigeration technologies of ferroelectrics have given rise to significant improvement of environmental problems. Anisotropy of the electrocaloric effect (ECE), as a hopefully effective method to promote EC properties, needs further investigation because of the unclear promotional mechanism of anisotropic domain responses on the ECE. Here, we achieve a significantly enhanced ECE of anisotropic bulk KTa 1−x Nb x O 3 (KTN) single crystals and reveal the promotional mechanism of anisotropic ECE induced by switching of different domain structures. The adiabatic temperature change (ΔT) of KTN along the [111] C direction is improved by nearly 120% compared with that of KTN along [001] C . Simultaneously, a large EC strength (ΔT/ΔE) of 0.33 K mm kV −1 is obtained along the [111] C direction under a low driving electric field. Furthermore, we illuminate that the coexistence of like-orthogonal configurations and tetragonal structures induced by the electric field leads to much higher disorder along the [111] C direction than the other two directions. Additionally, free energy with triple potential wells is formed because of the like-multiphase coexistence by simulation, which is fundamentally responsible for the larger ΔT of [111] C .The study of revealing the impact on the ECE from anisotropic domain responses provides an effective approach to promote EC performance of ferroelectrics with pronounced anisotropy (perovskites, Aurivillius phase, tungsten bronzes, etc).

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“…Aiming at the close relationship between polarization and the pyroelectric effect, the ECE was first measured using x = 0.05 as an example owing to its highest piezoelectricity, to understand the process of polarization changes under both electric field and temperature. The ECE is the process of heat absorption or release through the phase change and dipole entropy change of ferroelectrics induced by an electric field 33–35 . Figure 6A shows a schematic of the ECE at the micro‐level.…”

Section: Resultsmentioning

confidence: 99%

Enhanced pyroelectric performance in potassium sodium niobate‐based ceramics via multisymmetries coexistence design

et al. 2022

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Achieving excellent pyroelectric performance remains a challenge for lead‐free piezoelectric ceramics. To meet the requirements of both an enhanced pyroelectric coefficient at room temperature and good thermal stability during the encapsulation of pyroelectric devices, (1–x)K0.48Na0.52NbO3–xBi0.5Ag0.5ZrO3–0.2%Fe2O3 (KNN–BAZ–Fe) lead‐free ferroelectric ceramics with high Curie temperatures were prepared to obtain improved pyroelectric performance via the coexistence of multiple symmetries. The variation of BAZ content led to the formation of rhombohedral–orthorhombic–tetragonal phase boundary and promoted grain growth, resulting in the best pyroelectric coefficient (p = 5.09 × 10−4 C m−2°C−1) and enhanced figures of merit (Fi = 0.2084 × 10−9 (m V−1), Fv = 0.0142 m2 C−1, Fd = 0.0947 × 10−4 Pa−1/2, and Fe = 17.66 J m−3 K−2) for infrared (IR) detection when x = 0.05. The room‐temperature pyroelectric coefficient obtained in this study is approximately four times that of the pure KNN ceramic and is the maximum value reported for niobate‐based piezoelectric ceramics. Moreover, compared with the poor thermal stability of barium titanate‐ and bismuth sodium titanate‐based ceramics because of their ultralow Curie temperature or thermal depolarization temperature, the ceramics investigated here exhibit much better thermal stability because of their high Curie temperature (TC > 300°C) and diffused phase‐transition behavior, making them more adaptable for practical applications. These results suggest that KNN–xBAZ–Fe ceramics are attractive candidates for applications in the field of IR sensors.

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Study of electrocaloric effect in lead-free 0.9K0.5Na0.5NbO3–0.1CaZrO3 solid solution ceramics

Cited by 11 publications

References 35 publications

Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Enhanced Electrocaloric Effect Induced by the Electric-Field-Generated Like-Multiphase Coexistence in Anisotropic KTa_1–xNb_xO₃ Single Crystals

Enhanced pyroelectric performance in potassium sodium niobate‐based ceramics via multisymmetries coexistence design

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Study of electrocaloric effect in lead-free 0.9K0.5Na0.5NbO3–0.1CaZrO3 solid solution ceramics

Cited by 11 publications

References 35 publications

Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Enhanced electrocaloric effect in compositional driven potassium sodium niobate‐based relaxor ferroelectrics

Enhanced Electrocaloric Effect Induced by the Electric-Field-Generated Like-Multiphase Coexistence in Anisotropic KTa1–xNbxO3 Single Crystals

Enhanced pyroelectric performance in potassium sodium niobate‐based ceramics via multisymmetries coexistence design

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Enhanced Electrocaloric Effect Induced by the Electric-Field-Generated Like-Multiphase Coexistence in Anisotropic KTa_1–xNb_xO₃ Single Crystals