Thermophysical property evaluation of rare‐earth hafnate RE2Hf2O7 as long‐life service neutron absorber component.
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| Title: | Thermophysical property evaluation of rare‐earth hafnate RE |
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| Authors: | Zhu, Shuyi1,2 (AUTHOR), Mu, Jiawei1,2 (AUTHOR), Shi, Yanli1,2 (AUTHOR), Lu, Kailei1,2 (AUTHOR), Chen, Lin3 (AUTHOR), Qi, Jianqi1,2,4 (AUTHOR) qijianqi@scu.edu.cn, Lu, Tiecheng1,2,4 (AUTHOR) |
| Source: | Journal of the American Ceramic Society. Sep2025, Vol. 108 Issue 9, p1-10. 10p. |
| Subjects: | Control elements (Nuclear reactors), Neutron absorbers, Nuclear reactor control, Neutron capture, Thermophysical properties |
| Abstract: | Control rods are essential components in nuclear reactors, used to maintain the desired state of fission reactions. Among potential materials for this application, RE2Hf2O7 compounds exhibit exceptional neutron absorption capacity and structural stability under prolonged radiation exposure, minimizing the risk of reduced neutron absorption efficiency. Herein, dense RE2Hf2O7 ceramics (RE = Eu, Gd, Tb, Dy, Tm) were synthesized via vacuum solid‐state reactive sintering. Structural analysis revealed distinct phase formations: Eu2Hf2O7, Gd2Hf2O7, and Tb2Hf2O7 crystallized in the pyrochlore structure, while Dy2Hf2O7 and Tm2Hf2O7 adopted a defective fluorite configuration. The thermophysical properties of these ceramics were systematically evaluated. RE2Hf2O7 demonstrated superior thermal conductivity (1.4‐2.4 W·m−1·K−1, 298–1073 K) compared to the conventional material Dy2TiO5. Furthermore, their thermal expansion coefficients (6.0–10.5 × 10−6 K−1, 350–1100 K) closely matched those of Dy2TiO5 (7.5–10.5 × 10−6 K−1), ensuring compatibility in reactor environments. Mechanical testing indicated robust performance, with Vickers hardness values ranging from 12.6 to 14.9 GPa, attributed to high bulk density and enhanced atomic bond strength. This work highlights the feasibility of tailoring RE2Hf2O7 ceramics through rare‐earth and hafnium composition adjustments, offering a pathway to durable, high‐performance neutron absorbers. The combined thermal, mechanical, and structural advantages position these materials as promising candidates for next‐generation nuclear reactor control rods. [ABSTRACT FROM AUTHOR] |
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| Database: | Engineering Source |
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| Abstract: | Control rods are essential components in nuclear reactors, used to maintain the desired state of fission reactions. Among potential materials for this application, RE2Hf2O7 compounds exhibit exceptional neutron absorption capacity and structural stability under prolonged radiation exposure, minimizing the risk of reduced neutron absorption efficiency. Herein, dense RE2Hf2O7 ceramics (RE = Eu, Gd, Tb, Dy, Tm) were synthesized via vacuum solid‐state reactive sintering. Structural analysis revealed distinct phase formations: Eu2Hf2O7, Gd2Hf2O7, and Tb2Hf2O7 crystallized in the pyrochlore structure, while Dy2Hf2O7 and Tm2Hf2O7 adopted a defective fluorite configuration. The thermophysical properties of these ceramics were systematically evaluated. RE2Hf2O7 demonstrated superior thermal conductivity (1.4‐2.4 W·m−1·K−1, 298–1073 K) compared to the conventional material Dy2TiO5. Furthermore, their thermal expansion coefficients (6.0–10.5 × 10−6 K−1, 350–1100 K) closely matched those of Dy2TiO5 (7.5–10.5 × 10−6 K−1), ensuring compatibility in reactor environments. Mechanical testing indicated robust performance, with Vickers hardness values ranging from 12.6 to 14.9 GPa, attributed to high bulk density and enhanced atomic bond strength. This work highlights the feasibility of tailoring RE2Hf2O7 ceramics through rare‐earth and hafnium composition adjustments, offering a pathway to durable, high‐performance neutron absorbers. The combined thermal, mechanical, and structural advantages position these materials as promising candidates for next‐generation nuclear reactor control rods. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 00027820 |
| DOI: | 10.1111/jace.20709 |
