| Autor: |
Ye, Meiyan, Zhou, Yiyang, Shao, Tianyin, Liu, Haozhe, Tao, Qiang, Wang, Xin, Tang, Ruilian, Yue, Huijuan, Li, Yan, Zhu, Pinwen |
| Zdroj: |
The Journal of Physical Chemistry - Part C; April 2023, Vol. 127 Issue: 13 p6543-6551, 9p |
| Abstrakt: |
The pressure effects on the optical and structural properties of NiWO4have been studied experimentally and theoretically. The fundamental bandgap decreases with a pressure coefficient of −12.0 ± 0.2 meV/GPa. Meanwhile, the Ni2+d–d transition energies increase at a rate of 7.4–14.8 meV/GPa. Therefore, the energy differences between the fundamental band and the Ni2+d–d transition bands gradually decrease under pressure, which is beneficial to improve its optical performance. These optical phenomena are associated with structural variations. The shrinkage of the WO6octahedron enhances the hybridization between the W 5d and O 2p orbitals, resulting in bandgap reduction. The pressure-induced enhancement of the NiO6octahedral symmetry increases the crystal field splitting, thereby yielding increases in the Ni2+d–d intraband transition energies. Besides, a pressure-induced structural phase transition is also observed around 20.0 GPa by both angle-dispersive synchrotron X-ray diffraction (ADXRD) and Raman experiments. This study provides valuable insight into the electron–lattice coupling of NiWO4under compression and an effective way to modulate the electronic structure and optical properties of isomorphic wolframite materials. |
| Databáze: |
Supplemental Index |
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