Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures
An emerging class of superhard materials for extreme environment applications are compounds formed by heavy transition metals with light elements. In this work, ultrahigh pressure experiments on transition metal rhenium diboride (<i>ReB<sub>2</sub></i>) were carried out in a...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-04-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/13/7/1657 |
| _version_ | 1797571553152466944 |
|---|---|
| author | Kaleb C. Burrage Chia-Min Lin Wei-Chih Chen Cheng-Chien Chen Yogesh K. Vohra |
| author_facet | Kaleb C. Burrage Chia-Min Lin Wei-Chih Chen Cheng-Chien Chen Yogesh K. Vohra |
| author_sort | Kaleb C. Burrage |
| collection | DOAJ |
| description | An emerging class of superhard materials for extreme environment applications are compounds formed by heavy transition metals with light elements. In this work, ultrahigh pressure experiments on transition metal rhenium diboride (<i>ReB<sub>2</sub></i>) were carried out in a diamond anvil cell under isothermal and non-hydrostatic compression. Two independent high-pressure experiments were carried out on <i>ReB<sub>2</sub></i> for the first time up to a pressure of 241 GPa (volume compression <i>V/V<sub>0</sub></i> = 0.731 ± 0.004), with platinum as an internal pressure standard in X-ray diffraction studies. The hexagonal phase of <i>ReB<sub>2</sub></i> was stable under highest pressure, and the anisotropy between the <i>a</i>-axis and <i>c</i>-axis compression increases with pressure to 241 GPa. The measured equation of state (EOS) above the yield stress of <i>ReB<sub>2</sub></i> is well represented by the bulk modulus <i>K<sub>0</sub></i> = 364 GPa and its first pressure derivative <i>K<sub>0</sub>´</i> = 3.53. Corresponding density-functional-theory (DFT) simulations of the EOS and elastic constants agreed well with the experimental data. DFT results indicated that <i>ReB<sub>2</sub></i> becomes more ductile with enhanced tendency towards metallic bonding under compression. The DFT results also showed strong crystal anisotropy up to the maximum pressure under study. The pressure-enhanced electron density distribution along the <i>Re</i> and <i>B</i> bond direction renders the material highly incompressible along the <i>c</i>-axis. Our study helps to establish the fundamental basis for anisotropic compression of <i>ReB<sub>2</sub></i> under ultrahigh pressures. |
| first_indexed | 2024-03-10T20:42:05Z |
| format | Article |
| id | doaj.art-89d5acda4a4445759111bbd81028e8dd |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T20:42:05Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-89d5acda4a4445759111bbd81028e8dd2023-11-19T20:35:03ZengMDPI AGMaterials1996-19442020-04-01137165710.3390/ma13071657Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh PressuresKaleb C. Burrage0Chia-Min Lin1Wei-Chih Chen2Cheng-Chien Chen3Yogesh K. Vohra4Department of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USADepartment of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USADepartment of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USADepartment of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USADepartment of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USAAn emerging class of superhard materials for extreme environment applications are compounds formed by heavy transition metals with light elements. In this work, ultrahigh pressure experiments on transition metal rhenium diboride (<i>ReB<sub>2</sub></i>) were carried out in a diamond anvil cell under isothermal and non-hydrostatic compression. Two independent high-pressure experiments were carried out on <i>ReB<sub>2</sub></i> for the first time up to a pressure of 241 GPa (volume compression <i>V/V<sub>0</sub></i> = 0.731 ± 0.004), with platinum as an internal pressure standard in X-ray diffraction studies. The hexagonal phase of <i>ReB<sub>2</sub></i> was stable under highest pressure, and the anisotropy between the <i>a</i>-axis and <i>c</i>-axis compression increases with pressure to 241 GPa. The measured equation of state (EOS) above the yield stress of <i>ReB<sub>2</sub></i> is well represented by the bulk modulus <i>K<sub>0</sub></i> = 364 GPa and its first pressure derivative <i>K<sub>0</sub>´</i> = 3.53. Corresponding density-functional-theory (DFT) simulations of the EOS and elastic constants agreed well with the experimental data. DFT results indicated that <i>ReB<sub>2</sub></i> becomes more ductile with enhanced tendency towards metallic bonding under compression. The DFT results also showed strong crystal anisotropy up to the maximum pressure under study. The pressure-enhanced electron density distribution along the <i>Re</i> and <i>B</i> bond direction renders the material highly incompressible along the <i>c</i>-axis. Our study helps to establish the fundamental basis for anisotropic compression of <i>ReB<sub>2</sub></i> under ultrahigh pressures.https://www.mdpi.com/1996-1944/13/7/1657transition metal boridessuperhard materialshigh pressure studiesdiamond anvil cellab initio calculationselastic constants |
| spellingShingle | Kaleb C. Burrage Chia-Min Lin Wei-Chih Chen Cheng-Chien Chen Yogesh K. Vohra Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures Materials transition metal borides superhard materials high pressure studies diamond anvil cell ab initio calculations elastic constants |
| title | Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures |
| title_full | Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures |
| title_fullStr | Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures |
| title_full_unstemmed | Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures |
| title_short | Experimental and Computational Studies on Superhard Material Rhenium Diboride under Ultrahigh Pressures |
| title_sort | experimental and computational studies on superhard material rhenium diboride under ultrahigh pressures |
| topic | transition metal borides superhard materials high pressure studies diamond anvil cell ab initio calculations elastic constants |
| url | https://www.mdpi.com/1996-1944/13/7/1657 |
| work_keys_str_mv | AT kalebcburrage experimentalandcomputationalstudiesonsuperhardmaterialrheniumdiborideunderultrahighpressures AT chiaminlin experimentalandcomputationalstudiesonsuperhardmaterialrheniumdiborideunderultrahighpressures AT weichihchen experimentalandcomputationalstudiesonsuperhardmaterialrheniumdiborideunderultrahighpressures AT chengchienchen experimentalandcomputationalstudiesonsuperhardmaterialrheniumdiborideunderultrahighpressures AT yogeshkvohra experimentalandcomputationalstudiesonsuperhardmaterialrheniumdiborideunderultrahighpressures |