Dual-phase rare-earth-zirconate high-entropy ceramics with glass-like thermal conductivity

Zhu, Jiatong; Meng, Xuanyu; Zhang, Ping; Li, Zhuolun; Xu, Jie; Reece, Michael J.; Gao, Feng

doi:10.1016/j.jeurceramsoc.2020.11.047

Cited by 126 publications

(49 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to YSZ, which is the most promising TBC materials, high‐entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides exhibit similar TECs and much lower thermal conductivity, which make them distinct from the other promising TBC materials. [ 25,51–62 ] Figure 7B shows the XRD patterns of high‐entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides after being treated at 1500°C for 50 h. It is obvious that there is no detectable phase decomposition or transformation can be observed, indicating the superior phase stability of high‐entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides under high‐temperature and long‐term thermal exposure conditions.…”

Section: Resultsmentioning

confidence: 99%

“…(A) The thermal conductivity versus TECs for the high‐entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides as well as other conventional TBC materials [ 25,51–62 ] ; (B) the phase stability of high‐entropy RE 2 (Y 0.2 Yb 0.2 Nb 0.2 Ta 0.2 Ce 0.2 ) 2 O 7 oxides after thermal exposure at 1500°C for 50 h. TECs, thermal expansion coefficients; TBC, thermal barrier coating…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides

Wang

et al. 2022

J Am Ceram Soc.

View full text Add to dashboard Cite

Pursuing novel thermal barrier–coating materials with lower thermal conductivity and high‐temperature stability can simultaneously improve the working efficiency and service temperature of a gas turbine. In this study, a series of high‐entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 (RE = La, Nd, Sm, Gd, Dy, and Er) oxides were prepared though solid‐state reaction. Through tuning the rare‐earth cations, an order–disorder transition occurs from certain partially ordered weberite structure (C2221) to disordered defective fluorite structure (Fm3¯$\bar{3}$m). All the high‐entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides possess low thermal conductivity in the range of 0.91–1.34 W m−1 K−1 at room temperature, which can be attributed to increased lattice anharmonicity and disorder, resulting in additional phonon scattering. Herein, we proved that the incorporation of heterovalent cations at B‐sites in high‐entropy A2B2O7 crystals is an effective strategy to reduce the thermal conductivity without compromising the decrease of oxygen vacancy. Moreover, the high‐entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides show the relatively higher thermal expansion coefficients of 10.3–10.7 × 10−6°C−1 and excellent phase stability at elevated temperatures.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides

Wang

et al. 2022

J Am Ceram Soc.

View full text Add to dashboard Cite

show abstract

“…The cations and of O vacancies present disordered distributions [32]. to the (400) plane [33] and the lattice parameter was calculated to be 10.631 Å (based on the Equation ( 7)). The lattice parameters calculated from XRD patterns and density of the samples were shown in Table 1.…”

Section: Phase Stability and Structural Characterizationmentioning

confidence: 99%

High-entropy Rare-earth Zirconate Ceramics With Low Thermal Conductivity for Advanced Thermal Barrier Coatings

Liu

Shi

et al. 2021

Preprint

View full text Add to dashboard Cite

In this work, we have successfully fabricated a novel high-entropy rare-earth zirconate (La0.2Nd0.2Sm0.2Gd0.2Yb0.2)2Zr2O7 (5RE2Zr2O7) ceramics and its counterparts by using a new high-speed grinding strategy combined with typical solid-state reaction method. The X-ray diffraction (XRD) and Raman spectroscopy analysis indicated that the as-prepared 5RE2Zr2O7 ceramics performed single-phase defect fluorite-type structures with highly sintering resistant and excellent thermal stability. The possibility of formation of 5RE2Zr2O7 was verified via first-principles calculations. Meanwhile, the phase structure, thermophysical and mechanical properties of the samples were systematically investigated. The results showed that the 5RE2Zr2O7 ceramics demonstrated lower thermal conductivity (0.9-1.72 W·m-1·K-1) and higher thermal expansion coefficients (10.9 × 10-6 K-1 at 1273 K) than its counterparts. Furthermore, the 5RE2Zr2O7 ceramics presented outstanding mechanical properties including large Young’s modulus (186-257 GPa), higher fracture toughness and lower brittleness index than that of YSZ. Therefore, in view of various excellent properties, the as-prepared 5RE2Zr2O7 ceramics possess great potential for applications in the field of thermal barrier coatings.

show abstract

“…Previous studies have shown that the smaller and heavier solution element of “rattling” effect could induce resonant phonon scattering in HECs, forming a glass‐like thermal conductivity 27,28 . In this work, we introduced “Yb” element into the traditional equimolar high‐entropy component (La 0.25 Nd 0.25 Sm 0.25 Gd 0.25 ) 2 Zr 2 O 7 to form ((La 0.25 Nd 0.25 Sm 0.25 Gd 0.25 ) 0.75 Yb 0.25 ) 2 Zr 2 O 7.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies have shown that the smaller and heavier solution element of "rattling" effect could induce resonant phonon scattering in HECs, forming a glasslike thermal conductivity. 27,28 In this work, we introduced "Yb" element into the traditional equimolar highentropy component (La 0.25 Nd 0.25 Sm 0.25 Gd 0.25 ) 2 Zr 2 O 7 to form ((La 0.25 Nd 0.25 Sm 0.25 Gd 0.25 ) 0.75 Yb 0.25 ) 2 Zr 2 O 7. The process of precursor solution to precursor fibers by electrospinning, the phase structure, and the microscopic morphology at different calcination temperatures were investigated in details.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ultra‐fine rare‐earth‐zirconate high‐entropy ceramic fibers via electrospinning

Wei

Yang

et al. 2022

J Am Ceram Soc.

Self Cite

View full text Add to dashboard Cite

Ceramic fibers have the advantages of low density, high strength, high temperature resistance, and excellent mechanical vibration resistance. In this work, sol-gel and electrospinning were used to prepare ultra-fine rareearth-zirconate high-entropy ceramic (HEC) fibers with the composition of ((La 0.25 Nd 0.25 Sm 0.25 Gd 0.25 ) 0.75 Yb 0.25 ) 2 Zr 2 O 7 . The decomposition process and microscopic morphology of the fibers were characterized by thermogravimetry/differential scanning calorimetry, Fourier transform infrared and scanning electron microscope. The results indicated that defective fluorite-structured fibers with a smooth surface were obtained by calcining at 900-1000 • C, while fibers with the pyrochlore structure and the diameter within 140 nm were obtained by calcining at temperature higher than 1100 • C. The HEC fibers still maintain a continuous microstructure on the surface after calcination. In addition, the porous ceramics prepared from HEC fibers have a comparatively low thermal conductivity (0.22 ± 0.05 W m −1 K −1 , 25 • C). These promising properties indicate that the HEC fibers could be candidate materials for thermal-insulation application.

show abstract

Dual-phase rare-earth-zirconate high-entropy ceramics with glass-like thermal conductivity

Cited by 126 publications

References 36 publications

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides

High-entropy Rare-earth Zirconate Ceramics With Low Thermal Conductivity for Advanced Thermal Barrier Coatings

Synthesis of ultra‐fine rare‐earth‐zirconate high‐entropy ceramic fibers via electrospinning

Contact Info

Product

Resources

About

Dual-phase rare-earth-zirconate high-entropy ceramics with glass-like thermal conductivity

Cited by 126 publications

References 36 publications

Phase evolution and thermophysical properties of high‐entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides

Phase evolution and thermophysical properties of high‐entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)2O7 oxides

High-entropy Rare-earth Zirconate Ceramics With Low Thermal Conductivity for Advanced Thermal Barrier Coatings

Synthesis of ultra‐fine rare‐earth‐zirconate high‐entropy ceramic fibers via electrospinning

Contact Info

Product

Resources

About

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides

Phase evolution and thermophysical properties of high‐entropy RE₂(Y_0.2Yb_0.2Nb_0.2Ta_0.2Ce_0.2)₂O₇ oxides