Lee Sung Keun, Mibe Kenji, Fei Yingwei, Cody George D, Mysen Bjorn O
School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742 Korea.
Phys Rev Lett. 2005 Apr 29;94(16):165507. doi: 10.1103/PhysRevLett.94.165507.
We report spectroscopic evidence for the pressure-induced structural changes in B2O3 glass quenched from melts at pressures up to 6 GPa using solid-state NMR. While all borons are tri-coordinated at 1 atm, the fraction of tetra-coordinated boron increases with pressure, being about 5% and 27% in the B2O3 glass quenched from melts at 2 and 6 GPa, respectively. The fraction of boroxol ring species increases with pressure up to 2 GPa and apparently decreases with further compression up to 6 GPa. Two densification mechanisms are proposed to explain the variation of boron species with pressure.
我们报告了使用固态核磁共振技术获得的光谱证据，证明了在高达6吉帕的压力下，从熔体淬火得到的B2O3玻璃中压力诱导的结构变化。在1个大气压下，所有硼原子都是三配位的，而四配位硼的比例随压力增加，在从2吉帕和6吉帕熔体淬火得到的B2O3玻璃中分别约为5%和27%。硼氧环物种的比例在压力达到2吉帕时增加，在进一步压缩至6吉帕时明显减少。提出了两种致密化机制来解释硼物种随压力的变化。
