Materials Today Physics
·
2023
·
IF 11.5
Lin Chen,Mingyu Hu,Jing Feng
Thermal transport management is of great significance for materials such as thermal barrier coatings , photovoltaics , and thermoelectrics . In particular, tremendous efforts have been made to tailor phonon thermal transport to improve performance. This work elucidated origins of low thermal conductivity of ferroelastic (Sm 1-X Yb X )TaO 4 solid solutions from defect-dominated phonon scattering processes. We estimated the influences of point defects (misfits in atomic weight and ionic radius , and oxygen vacancies), ferroelastic domains, and the Umklapp process on thermal transports via the corresponding phonon relaxation time ( τ ). The phonon relaxation time caused by point defects ( τ D ), ferroelastic domains ( τ F ), and the Umklapp process ( τ U ) exhibited a trend of τ D − 1 > τ U − 1 > τ F − 1 , indicating that point defects dominated the thermal transports. The effects of ferroelastic domains on thermal conductivity were estimated according to domain widths and space mismatches between neighboring domains. The approximately parallel relationship between the neighboring domains was beneficial for reducing ferroelastic t - m transition energy. Furthermore, a model was developed to derive the high-temperature thermal conductivity, and the contributions of radiative thermal conductivity were separated from the total thermal conductivity. The analysis of thermal transports can be used in other materials to estimate the contributions of different thermal transport mechanisms to the total thermal conductivity at both low and high temperatures, and to effectively tailor thermal transports according to specific applications.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2020
·Vol. 8
·期 5
·1197-1204
·
IF 5.958
Xiao-Qin Xu,Hua Zhang,Xue-Qin Huang,Yu-Ling Liu
Ferroelastic materials have attracted wide attention due to their great application prospects in energy and information conversion, data storage applications, etc. In this report, we designed and synthesized an organic–inorganic hybrid halide perovskite ferroelastic (TMTB)CdCl3 (TMTB: N,N,N-trimethyl-tert-butylammonium) under the quasi-spherical strategy. (TMTB)CdCl3 shows a structural phase transition at around 356 K (Tc). In the ferroelastic phase, a quasi-spherical TMTB cation is orientationally ordered with the symmetry of mmm. Above the Tc in the paraelastic phase, the crystal symmetry of 6/mmm compels the TMTB cation with multiple orientations showing spherical distribution. The phase transition with an Aizu notation of 6/mmmFmmm agrees well with one of the 94 ferroelastic species. Under a polarized light microscope, the evolution of ferroelastic domains was visually observed. The calculated spontaneous strain value of (TMTB)CdCl3 is 0.0507 based on the lattice parameters. Moreover, (TMTB)CdCl3 shows prominent ‘ON’/‘OFF’ dielectric switches with good reproducibility. Theoretical calculations based on density functional theory (DFT) were further performed to explore the ‘spherical’ – ‘quasi-spherical’ variation of the TMTB cation. This work demonstrates that the quasi-spherical molecular strategy provides a shortcut for discovering new molecular ferroelastic materials, and also provides guidance for the directional design of functional materials.
研究领域:
材料科学
·
凝聚态物理
·
无机化学
·
应用物理
·
纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yinyi Luo,Lin Chen,Peng Wu,Peng Song,Jing Feng
Monoclinic phase SmNb 1-X Ta X O 4 ceramics are synthesized via solid-state reaction. X-ray diffraction and Raman spectra are applied to characterize the crystal structure. The ferroelasticity of SmNb 1-X Ta X O 4 ceramics is confirmed by the domain structure observed via scanning electron microscopy. The band gap of SmNb 1-X Ta X O 4 ceramics ranges from 4.3 to 5.0 eV and they exhibit excellent absorption for UV light. Thermophysics properties including specific heat, thermal diffusivity , thermal conductivity and thermal expansion coefficients of SmNb 1-X Ta X O 4 ceramics are investigated systematically. The result shows that the thermal conductivity of SmNb 1-X Ta X O 4 ceramics is as low as 1.33 W m −1 K −1 (900 °C) and the thermal expansion coefficients are as high as 11.7 × 10 −6 K −1 (1200 °C). The unique ferroelasticity and outstanding thermophysics properties indicate that SmNb 1-X Ta X O 4 ceramics are promising thermal barrier coating materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Materialia
·
2018
·
IF 0
Peng Wu,Mingyu Hu,Lin Chen,Wei Chen,Xiaoyu Chong,Hui Gu,Jing Feng
A series of ceramics of (Y 1-x Dy x )TaO 4 monoclinic phases (space group: I2 (5)) are prepared by the solid-state reaction method. The high-resolution transmission electron microscopy (HRTEM) suggest the (Y 1-x Dy x )TaO 4 ceramics possess ferroelastic domain, which is derived from reversible second-order ferroelastic transformation between the high-temperature tetragonal (t) and low-temperature monoclinic (m) phase. Similar to metastable tetragonal YSZ ceramics, the ferroelastic toughening mechanism may exist in m-phase (Y 1-x Dy x )TaO 4 ceramics through the shift or reorientation of ferroelastic domain under the stress field of a crack. The energy dispersive spectroscopy reveals that the elements of Y and Dy are inhomogeneous in the grain of (Y 1-x Dy x )TaO 4 ceramics, which breaks down the relationship of concave parabola between thermal conductivity and composition parameter (x). Moreover, the thermal conductivities (1.7–2.0 W/m/k at 900 ̊C) and thermal expansion coefficients (TECs) (10–11 × 10 −6 K −1 ) of (Y 1-x Dy x )TaO 4 ceramics are comparable to that of YSZ (yttria-stabilized zirconia). In view of the low thermal conductivity, high thermal expansion coefficients, good high-temperature phase stability and ferroelastic transformation, the (Y 1-x Dy x )TaO 4 ceramics show great potentials in the application of high-temperature thermal insulator materials, particularly as thermal barrier coatings .
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
CHINESE JOURNAL OF CHEMISTRY
·
2024
·
IF 5.5
Jia-Qi Luo,Meng-Meng Lun,Qiang-Qiang Jia,Zhi-Jie Wang,Hai-Feng Lu,Yi Zhang,Da-Wei Fu
Comprehensive Summary Molecular ferroelastics with the natural features of mechanical flexibility and switchable spontaneous strain have attracted widespread attention in the scientific community due to their potential applications in tunable gratings, flexible memorizers, strain sensors, and intelligent actuators. However, most designs of molecular ferroelastics remain in the stage of blind exploration, posing a challenge to achieve a functional ferroelastic more effectively. Herein, we have successfully obtained a molecular ferroelastic, [Me 2 NH(CH 2 ) 2 NH 3 ](ReO 4 ) 2 (Me 2 NH(CH 2 ) 2 NH 3 = N , N -dimethylethylenediammonium), under the guidance of the mono-/double-protonation strategy. The double-protonated [Me 2 NH(CH 2 ) 2 NH 3 ](ReO 4 ) 2 undergoes a paraelastic-ferroelastic phase transition with the Aizu notation of 2/ m F at 322 K. Meanwhile, the theoretical calculation and experimental measurement simultaneously show that [Me 2 NH(CH 2 ) 2 NH 3 ](ReO 4 ) 2 possesses good mechanical flexibility, because its elastic modulus ( E ) of 8.26 GPa and hardness ( H ) of 0.45 GPa are smaller than the average values of organic crystals ( E of 12.05 GPa and H of 0.5 GPa), which makes it promising to apply in wearable pressure sensors, implantable medical sensors, high-precision tuners, etc . This work further enriches the molecular ferroelastic family and demonstrates that mono-/double-protonation is one of the effective molecular modification strategies for designing ferroelastics.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 4
·2727-2740
·
IF 3.094
Fushuo Wu,Peng Wu,Yunxuan Zhou,Xiaoyu Chong,Jing Feng
In this work, RENbO 4 (RE = Y, La, Nd, Sm, Gd, Dy, Yb) ceramics with low density, low Young's modulus, low thermal conductivity, and high thermal expansion have been systematically investigated, the excellent thermo-mechanical properties indicate that RENbO 4 ceramics possess the potential as the new generation of thermal barrier coatings (TBCs) materials. X-ray diffraction and Raman spectroscopy phase structure identification reveal that all dense bulk specimens obtained by high-temperature solid-state reaction belonged to the monoclinic (m) phase with C12/c1 space group. The ferroelastic domains are detected in the specimens, revealing the ferroelastic transformation between tetragonal (t) and monoclinic (m) phases of RENbO 4 ceramics. The Young's modulus and hardness of the RENbO 4 ceramics measured by the NanoBlitz 3D nanoindentation method are discussed in details, and the lower Young's modulus (60-170 GPa) and higher hardness (the maximum value reaches 11.48 GPa) indicating that higher resistance of RENbO 4 ceramics to failure and damage. Lower thermal conductivity (1.42-2.21 W [m k] −1 at 500°C-900°C) and lower density (5.330-7.400 g/cm 3 ) than other typical TBCs materials give RENbO 4 ceramics the unique advantage of being new TBCs materials. Meanwhile, the thermal expansion coefficients of RENbO 4 ceramics reach 9.8-11.6 × 10 −6 k −1 and are comparable or higher than other typical TBCs materials. According to the first-order derivative of the thermal expansion rate, the temperature of the ferroelastic transformation of RENbO 4 ceramics can be observed.
研究领域:
材料科学
·
固体力学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 20
·30881-30887
·
IF 5.6
Zhenghuang Quan,Zhoufu Wang,Hao Liu,Yan Ma,Shen Zhou,Pingtao Fang,Chao Shu
Yttrium oxide material exhibits excellent vacuum and high-temperature chemical stability, making it an ideal first-choice refractory material for superalloy smelting. However, its poor fracture toughness and low thermal shock stability seriously limit its service life. The ferroelastic toughening phase LaNbO 4 provides excellent fracture toughness due to the ferroelastic domain switching toughening effect. This study focused on yttrium oxide materials, utilizing Y 2 O 3 , La 2 O 3 , and Nb 2 O 5 fine powders as the main raw materials. By incorporating ferroelastic functional unit characteristics, a pre-synthesis LaNbO 4 phase with good intrinsic fracture toughness was introduced into the Y 2 O 3 matrix. The effects of different LaNbO 4 contents on the phase composition, microstructure, mechanical properties, and thermal shock resistance of Y 2 O 3 /LaNbO 4 composite materials were subsequently investigated. The following results were obtained: 1) The optimal pre-synthesis temperature of LaNbO 4 was 1200 °C. At this temperature, LaNbO 4 powder with a fine grain and uniform grain size could be synthesized. 2) The Y 2 O 3 and LaNbO 4 phase resulted in mutual solid solution formation, leading to a change in grain size and mechanical strength of the Y 2 O 3 /LaNbO 4 composite material. 3) The addition of an appropriate amount of LaNbO 4 resulted in the formation of a structure filled with LaNbO 4 grains between the grain boundaries of Y 2 O 3 , effectively improving the fracture toughness and thermal shock stability of the materials. 4) The hardness and strength of LaNbO 4 were lower than the Y 2 O 3 phase, making the selection of LaNbO 4 phase addition to Y 2 O 3 crucial. The excessive addition of the LaNbO 4 phase caused the LaNbO 4 phase in the material to dominate. The hardness and strength of the Y 2 O 3 /LaNbO 4 composite materials were inferior to those of the Y 2 O 3 material, however, the fracture toughness and thermal shock stability improved due to the ferroelastic toughening effect. Therefore, an optimal amount of LaNbO 4 phase should be added to balance the fracture toughness and thermal shock stability of Y 2 O 3 /LaNbO 4 composite materials, while maintaining the hardness and strength of the Y 2 O 3 phase.
研究领域:
无机非金属材料
·
高温结构材料
·
陶瓷增韧
·
材料科学
·
热力学稳定性
·
粉末冶金
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Shuai Chen,Ding-Chong Han,Le Ye,Wei-Xiong Zhang
Hybrid ferroelastic crystals have emerged as a hot research topic in recent years owing to their prospective applications in piezoelectric sensors, mechanical switches, and optoelectronic devices. Nevertheless, most of the documented materials exhibit one-step or two-step ferroelastic phase transition(s), and those with multistep ferroelastic transitions are extremely scarce. We present a new hexagonal molecular perovskite based on a fluoro-substituted flexible cyclic ammonium cation, (1-fluoromethyl-1-methylpyrrolidine)[CdCl3] (1), undergoing unusual three-step ferroelastic phase transitions from hexagonal paraelastic phase to orthorhombic, monoclinic, and triclinic ferroelastic phases at 388, 376, and 311 K, respectively, with Aizu notation of 6/mmmFmmm, mmmF2/m, and 2/mF-1, featuring spontaneous strain of 0.002, 0.023, and 0.110, respectively. Furthermore, variable-temperature single-crystal diffraction reveals that the phase-transition mechanism in 1 principally originates from intriguing dynamic change of organic cations and synchronous displacement of inorganic chains. This scarce instance of multistep hybrid ferroelastic provides important clues for finding advanced ferroelastic materials.
研究领域:
材料科学
·
晶体学
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 49
·2303127
·
IF 13.3
Meng-Meng Lun,Chang-Yuan Su,Jie Li,Qiang-Qiang Jia,Hai-Feng Lu,Da-Wei Fu,Yi Zhang,Zhi-Xu Zhang
Organic–inorganic hybrid lead halide perovskites (OLHPs), represented by (CH 3 NH 3 )PbI 3 , are one of the research focus due to their exceptional performance in optoelectronic applications, and ferroelastic domain walls are benign to their charge carrier transport that is confirmed recently. Among them, the 1D OLHPs feature better stability against desorption and moisture, but related 1D ones possessing ferroelasticity are rarely investigated and reported so far. In this work, the 1D ferroelastic semiconductor ( N -iodomethyl- N -methyl-morpholinium)PbI 3 ((IDMML)PbI 3 ) is prepared successfully by introducing successively halogenate atoms from Cl, Br to I into the organic cation of the prototype ( N,N -dimethylmorpholinium)PbI 3 ((DMML)PbI 3 ). Notably, (IDMML)PbI 3 shows the narrow bandgap energy (≈2.34 eV) according to the ultraviolet-visible absorption spectrum and the theoretical calculation, and possesses the evident photoconductive characteristic with the on/off ratio of current of ≈50 under the 405 nm light irradiation. This work provides a new case for the ferroelastic OLHPs and will inspire intriguing research in the field of optoelectronic.
研究领域:
材料科学
·
光学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 6
·期 10
·1292-1300
·
IF 8.683
Yueyue He,Zhuo Chen,Xiaogang Chen,Xian-Ming Zhang,Dongying Fu
Organic–inorganic hybrid perovskite (OIHP) multifunctional molecular switching materials have been widely studied as excellent supplements to the conventional all-inorganic perovskites due to their structural diversity and property adjustability. However, considering their practical application, the phase transition temperature (Tp) of the system is a crucial evaluation standard and meanwhile it remains an arduous challenge to construct phase transition materials with three kinds of switching characteristics. Therefore, the design of high Tp multifunctional switching materials is a huge task. Herein, we have reported a chiral OIHP multifunctional semiconductor 2 ([(R)-N-fluoroethyl-3-quinuclidinol]PbBr3) with dielectric switching, nonlinear switching and ferroelastic switching characteristics and an ultrahigh Tp of 498 K, which is obtained from compound 1 ([(R)-N-ethyl-3-quinuclidinol]PbBr3) with a Tp of 445 K through the strategy of H/F substitution. The substitution of F atoms for H atoms not only changes the coordination environment of Pb, but also increases the molecular interactions due to the stronger electronegativity of the F atoms, which raises the barrier of rotation of the fluorinated organic cations, (R)-N-fluoroethyl-3-quinuclidinol, and finally leads to a remarkable increase in Tp. Ultimately, through accurate molecular design, the Tp of compound 2 has been increased by 53 K and compound 2 exhibits three kinds of switching characteristics, which also makes it a superior switching material for practical application.
研究领域:
材料科学
·
化学
·
物理学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Deqin Chen,Xiaowei Zhu,Siyu Xiong,Guobin Zhu,Laijun Liu,Jibran Khaliq,Chunchun Li
In this study, (La0.2Nd0.2Sm0.2Ho0.2Y0.2)(Nb1–xVx)O4 (0.1 ≤ x ≤ 0.4) ceramics were prepared using a high-entropy strategy via the solid-phase method. The crystal structure, microstructure, vibration modes, and phase transition were studied by X-ray diffraction, scanning electron microscopy/transmission electron microscopy (SEM/TEM), and Raman spectroscopy techniques. The phase of ceramics was confirmed to be a monoclinic fergusonite in the range of x ≤ 0.28, a tetragonal scheelite was in the range of 0.3 ≤ x ≤ 0.32, a complex phase of tetragonal scheelite, and zircon was observed in the ceramics when x ≥ 0.35. A zircon phase was also detected by TEM at x = 0.4. The ceramic at x = 0.25 exhibited outstanding temperature stabilization with εr = 18.06, Q × f = 56,300 GHz, and τf = −1.52 ppm/°C, while the x = 0.2 ceramic exhibited a low dielectric loss with εr = 18.14, Q × f = 65,200 GHz, and τf = −7.96 ppm/°C. Moreover, the permittivity, quality factor, and the temperature coefficient of resonance frequency were related to the polarizability, packing fraction, density, and the temperature coefficient of permittivity caused by phase transition. This is an effective method to regulate near-zero τf by the synergism of the high-entropy strategy and substituting Nb with V in LnNbO4 ceramics.
研究领域:
材料科学
·
电气工程
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Qing Liu,Xiaopeng Hu,Shenxiang Luo,Yu Zou,Jinwei Guo,Wang Zhu
First-principles calculations predict the quasi-static mechanical properties of the YTa 3 O 9 material. Orthorhombic phase YTa 3 O 9 ceramics, exhibiting a ferroelastic domain structure with two types of domains separated by 90° orientation differences, are synthesized by solid-state reaction. The mechanical properties and stress-strain behavior of the ceramics under various uniaxial compression loads are investigated through nanoindentation, Vickers indentation and universal testing machine equipped with digital image technology. The toughening mechanism is primarily governed by the layered structure, which promotes crack bifurcation, deflection, and bridging, together with the complex crack-propagation processes controlled by ferroelastic domain switching. Moreover, the stress–strain responses under various loading conditions and during cyclic compression exhibit the characteristic hysteresis of ferroelastic materials. No macroscopic fracture is observed during compression, owing to the increased energy barrier for crack propagation provided by the layered architecture and domain-switching mechanisms.
研究领域:
材料科学
·
陶瓷
·
力学性能
·
铁弹性
·
计算材料物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）