| Autor: |
Elena Bykova, Sergey V. Ovsyannikov, Maxim Bykov, Yuqing Yin, Timofey Fedotenko, Hendrik Holz, Stefan Gabel, Benoit Merle, Stella Chariton, Vitali B. Prakapenka, Natalia Dubrovinskaia, Alexander F. Goncharov, Leonid Dubrovinsky |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Journal of materials chemistry / A 10(37), 20111-20120 (2022). doi:10.1039/D2TA02268K special issue: "Journal of Materials Chemistry A Emerging Investigators" |
| DOI: |
10.1039/D2TA02268K |
| Popis: |
Tungsten tetraboride has been known so far as a non-stoichiometric compound with a variable composition (e.g. WB$_{4−x}$, WB$_{4+x}$). Its mechanical properties could exceed those of hard tungsten carbide, which is widely used nowadays in science and technology. The existence of stoichiometric WB$_4$ has not been proven yet, and its structure and crystal chemistry remain debatable to date. Here we report the synthesis of single crystals of the stoichiometric WB$_4$ phase under high-pressure high-temperature conditions. The crystal structure of WB$_4$ was determined using synchrotron single-crystal X-ray diffraction. In situ high-pressure compressibility measurements show that the bulk modulus of WB$_4$ is 238.6(2) GPa for B′ = 5.6(0). Measurements of mechanical properties of bulk polycrystalline sub-millimeter size samples under ambient conditions reveal a hardness of ∼36 GPa, confirming that the material falls in the category of superhard materials. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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