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| Main Authors: | , , , |
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| Format: | Artículo Open Access |
| Published: |
Wiley
2024
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| Subjects: | |
| Online Access: | https://ceramics.onlinelibrary.wiley.com/doi/10.1111/jace.19721 |
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Table of Contents:
- Isotropic negative thermal expansion in ZrW 2 O 8 and HfW 2 O 8 from 1100 to 1275°C Benjamin S. Hulbert Dylan W. Blake Gerard S. Mattei Waltraud M. Kriven Journal of the American Ceramic Society Abstract ZrW 2 O 8 (ZrO 2 •2WO 3 ) and HfW 2 O 8 (HfO 2 •2WO 3 ) have been the focus of thermal expansion studies due to their isotropic negative thermal expansion (NTE) measured previously at temperatures below 775°C. This work presents measurements of these materials at their thermodynamically stable temperature ranges of 1105 and 1257°C for ZrW 2 O 8 and 1105–1276°C for HfW 2 O 8 , where they were characterized with in situ, powder X‐ray diffraction. The linear coefficients of thermal expansion were measured to be −5.52 × 10 −6 and −4.87 × 10 −6 °C −1 for ZrW 2 O 8 and HfW 2 O 8 , respectively. The mechanism leading to this NTE is discussed. Powder samples were synthesized by a solution‐based process called the organic–inorganic steric entrapment method. In situ characterization in air was carried out at the National Synchrotron Light Source II using a hexapole lamp, optical furnace and the Advanced Photon Source using a quadrupole lamp, optical furnace to achieve elevated temperatures. 10.1111/jace.19721 http://creativecommons.org/licenses/by/4.0/