|
|
|
|
|
|
| The Effect of Non-Hydrostatic Pressure Environments on the High-Pressure Raman Phonons for U3O8 |
| WANG Yi-jia1, WU Bin-bin1, LIU Jing-yi1, FANG Lei-ming2, LIU Ben-qiong2, LEI Li1* |
1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
2. Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621022, China
|
|
|
|
|
Abstract The triuranium octoxide (U3O8) exhibits exceptional kinetic and thermodynamic stability among various uranium oxides. The study of the high-pressure phase stability and high-pressure phonon behaviour of U3O8 is an important reference for its application in the nuclear industry, catalysts, and other fields. Due to the complexity of the electron structure outside the nucleus of the uranium atoms ([Rn]5f36d17s2), compared to the oxygen atoms ([He]2s22p4), significant differences exist between their electron configurations. Therefore, synchrotron X-ray diffraction makes it difficult to detect subtle changes in U—O bonding for uranium oxides under high pressure. However, Raman spectroscopy is highly sensitive to changes in U—O bonding at high pressure, and it can reveal some important information about substances at high pressure, including bonding or stoichiometry. To date, the investigations on the high-pressure structural phase transition for U3O8 have typically focused on exploring its evolution in hydrostatic environments. However, a deep investigation of the effects of non-hydrostatic environments on the high-pressure phase transition of U3O8 has not been conducted yet. In this work, the effects of hydrostatic and non-hydrostatic environments on the high-pressure phase transition and phonon behaviour for orthorhombic α-U3O8 have been investigated using a high-pressure Raman scattering technique based on the diamond anvil cell. Our results show that initialization transition pressures of α-U3O8 under hydrostatic (8.1 GPa) and non-hydrostatic (8.2 GPa) conditions are very close. However, the significant micro zonation bias stress present within the sample in the non-hydrostatic environments leads to the completion transition pressure (16.4 GPa) being approximately 2 to 3 GPa lower compared to the corresponding values in the hydrostatic environments (18.5 GPa). The first-order pressure coefficients and mode-Grüneisen parameters γ of the main Raman modes in two comparison experiments were given. The results show that before the high-pressure phase transition, the absolute values of the zero-pressure first-order pressure coefficients |dω/dP| for the main Raman modes under the hydrostatic environments are generally greater than those under the non-hydrostatic environments, which indicates that the Raman modes exhibit an insignificant response to the pressure under the non-hydrostatic environments. However, the absolute values of the first-order pressure coefficients under the non-hydrostatic environments are significantly larger once the high-pressure phase transition begins. This may be caused by significant micro zonation bias stress that greatly strengthens the mutual coupling between the outer electrons of the uranium-oxygen atoms. The B(6)2 mode exhibits the smallest γ value at zero pressure, indicating a more positive response to external perturbations. Moreover, the first-order pressure coefficients of the A(3)2 and A(4)2 modes (representing the vibrations of the oxygen atoms along the a-axis) are typically smaller than those of the B(4)2 and B(6)2 modes (representing the displacements of the oxygen atoms in the bc-plane) when pressurized at room temperature, suggesting that the a-axis is less sensitive to pressure than the b-axis and c-axis before the high-pressure phase transition for α-U3O8. The effect of hydrostatic and non-hydrostatic environments on the high-pressure phase transition for α-U3O8 was investigated deeply for the first time in this work, which offered valuable insights into the high-pressure phase stability and lattice dynamics behavior of α-U3O8.
|
|
Received: 2024-03-31
Accepted: 2024-04-29
|
|
|
|
Corresponding Authors:
LEI Li
E-mail: lei@scu.edu.cn
|
|
[1] Hausen D M. The Journal of the Minerals, Maetals & Materials Society, 1998, 50(12)：45.
[2] Geng H Y, Song H X, Jin K, et al. Physical Review B, 2011, 84(17): 174115.
[3] Kvashnina K O, Butorin S M, Martin P, et al. Physical Review Letters, 2013, 111(25): 253002.
[4] Saniz R, Baldinozzi G, Arts I, et al. Physical Review Materials, 2023, 7(5): 054410.
[5] Lipp M J, Jenei Z S, Park Klepeis J, et al. No. LLNL-TR-522251. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States), 2011. (https://doi.org/10.2172/1034513)
[6] Zhang F X, Lang M, Wang J W, et al. Journal of Solid State Chemistry, 2014, 213: 110.
[7] Shukla B, Sanjay Kumar N R, Maji D, et al. Condensed Matter Physics, 2021. (https://www.researchgate.net/publication/350403673)
[8] Ranasinghe J I, Malakkal L, Jossou E, et al. Computational Materials Science, 2020, 171: 109264.
[9] Inaba H, Shimizu H，Naito K. Journal of Nuclear Materials, 1977, 64(1-2): 66.
[10] Labroche D, Dugne O, Chatillon C. Journal of Nuclear Materials, 2003, 312(1): 50.
[11] Miskowiec A, Spano T, Hunt R, et al. Physical Review Materials, 2020, 4(9): 093610.
[12] Lv B J, Xia Y H, Hu S L, et al. Physica Scripta, 2023, 98(7): 075921.
[13] Siegel S. Acta Crystallographica, 1955, 8(10): 617.
[14] Loopstra B O. Acta Crystallographica, 1964, 17(6): 651.
[15] Girdhar H L, Westrum E F. Journal of Chemical & Engineering Data, 1968, 13(4): 531.
[16] Loopstra B O. Journal of Applied Crystallography, 1970, 3(2): 94.
[17] LÜ Jun-bo, LI Gan, GUO Shu-lan(吕俊波, 李 赣, 郭淑兰). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2014, 34(2): 405.
[18] Huang Z Y, Ma L D, Zhang J B, et al. Journal of Nuclear Materials, 2022, 572: 154084.
[19] Mazumdar A，White G. Reports on Progress in Physics, 2019, 82(7): 076901.
[20] LIU Jing-yi, ZHANG Lei-lei, LEI Li, et al(刘静仪, 张雷雷, 雷 力, 等). Journal of Light Scattering(光散射学报), 2023, 35(1): 1.
[21] Fan C M, Liu S, Lei L, et al. Chinese Physics Letters, 2022, 39(2): 026401.
[22] TAO Yu, LIU Jing-yi, LEI Li, et al(陶 雨, 刘静仪, 雷 力, 等). Journal of Light Scattering(光散射学报), 2022, 34(4): 261.
[23] Zhang L L, Cheng Y, Lei L, et al. Journal of Raman Spectroscopy, 2019, 50(12): 1962.
[24] Tang Q Q, Liu S, Lei L, et al. Journal of Raman Spectroscopy, 2020, 51(7): 1240.
[25] Mao H K, Bell P M, Shaner J T, et al. Journal of Applied Physics, 1978, 49(6): 3276.
[26] Butler I S, Allen G C, Tuan N A. Applied Spectroscopy, 1988, 42(5): 901.
[27] GUO Lin-yuan, GAO Tao, YANG Jin-wen(郭琳媛, 高 涛, 杨金文). Journal of Southwest University for Nationalities (Natural Science Edition)[西南民族大学学报(自然科学版)], 2014, 40(3): 402.
[28] Feng Z Z, Jia T T, Zhang J H, et al. Physical Review B, 2017, 96(23): 235205.
[29] Xiao Y, Chang C, Pei Y L, et al. Physical Review B, 2016, 94(12): 125203.
|
| [1] |
WANG Shi-xia, WANG Xiao-yu, HU Tian-yi. Study on Photocatalysis & Light Absorption and High-Pressure Structural Properties of ZnSe and Its Mn Doping Composites[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2024, 44(02): 380-385. |
| [2] |
XIAO Wan-sheng1,ZHANG Hong1,TAN Da-yong1,WENG Ke-nan1,LI Yan-chun2,LUO Chong-ju2,LIU Jing2, XIE Hong-sen3. Raman Characterization of Rutile Phase Transitions under High-Pressure and High-Temperature[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2007, 27(07): 1340-1343. |
|
|
|
|
