摘要
在室温条件下，利用金刚石对顶砧高压技术，对叠氮化钡进行了原位高压拉曼光谱研究，采用红宝石荧光压标测压，实验的最高压力为10GPa。实验压力范围内拉曼光谱随压力增加发生了丰富的变化。由于多处拉曼峰的出现和消失并伴随频移有拐点，我们判断叠氮化钡在3GPa左右时发生了第一次结构相变；随着压力继续增加，在3．5～6．5GPa范围内拉曼光谱仍不断变化，我们判断可能是相变或者是N=N=N键角和两个键长的非对称压缩导致的；压力继续增加，在8GPa左右，多处新峰出现和峰的劈裂表明又发生了一次结构相变，并且判断叠氮化钡向着更复杂的结构转变。通过实验可以确定，实验压力范围内N=N=N离子并未被破坏。其实验结果有待高压同步辐射实验的进一步确认。
Barium azide （Ba（N3）2） was investigated by in-situ high pressure Raman scattering spec- troscopy up to 10 GPa by use of a diamond anvil cell at room temperature. Pressures were deter- mined by ruby fluorescence. A variety of changes have been observed with pressure increasing at the experimental pressure range. Barium azide underwent a structure phase transition at about 3 GPa, accompanied by appearance and disappearance of several Raman peaks and a turning point of frequency. Raman spectroscopy continued to change at the range of 3.5 - 6.5 GPa, it possibly a phase transition or a change of N = N = N bond angle and asymmetric compression of the bond length. With the increase of pressure, several new peaks appeared and several peaks split around 8 GPa suggested a another phase transition occurred and barium azide transforms into a more com- plex structure. In our experiment, the azide ions were not been destroyed. Our experimental results need to be further confirmed by high-pressure synchrotron x-ray diffraction.
出处
《光散射学报》
北大核心
2014年第1期49-53,共5页
The Journal of Light Scattering
基金
国家自然科学基金资助项目(11304111
51172087
11147007
11304139)
国家教育部博士点基金资助项目(20110061110011)
中国博士后科学基金(2013M541284)
国家重点基础研究发展计划项目(2011CB808204)
关键词
拉曼光谱
高压
叠氮化钡
相变
Raman
high pressure
barium azide
phase transition
