【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10 GPa。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3 GPa左右时发生了第一次结构相变;随着压力继续增加,在3.5~6.5 GPa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8 GPa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。更多还原

【Abstract】 Barium azide(Ba(N3)2) was investigated by in-situ high pressure Raman scattering spectroscopy up to 10 GPa by use of a diamond anvil cell at room temperature. Pressures were determined 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 complex 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.更多还原