The pressure-induced metallic amorphous state of SnI4. II. Lattice vibrations at the crystal-to-amorphous phase transition studied by Raman scattering
The pressure-induced metallic amorphous state of SnI4. II. Lattice vibrations at the crystal-to-amorphous phase transition studied by Raman scattering
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DOI：
10.1088/0022-3719/18/4/011
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发表时间：
1985-02
期刊：
影响因子：
--
通讯作者：
S. Sugai
中科院分区：
文献类型：
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作者：
S. Sugai
关于pt.，见同上，第18卷，第789页(1985)。用高温高压拉曼光谱研究了分子晶体SnI_4的晶格振动。这种材料在1.5、10和20 Gpa的增压过程中显示出连续的相变。在20 Gpa以上，实现了无定形状态。在降低压力的情况下，这种无定形状态持续到大约2 Gpa。在这个压力下，在非常接近大气压的情况下，结构转变为另一个非晶态，然后是一个新的晶相。在高压无定形状态下，由SnI4四面体分子的呼吸模式产生的强A1对称峰分裂成双重态。这被解释为压力诱导的二聚化。还测量了液体的光谱，并与非晶态的光谱进行了比较。
For pt.I see ibid., vol.18, p.789 (1985). The lattice vibrations in the molecular crystal SnI4 have been investigated by high-pressure and high-temperature Raman spectroscopy. This material shows successive phase transitions at about 1.5, 10 and 20 GPa in a pressure-increasing process. Above 20 GPa an amorphous state is realised. On decreasing the pressure this amorphous state persists to about 2 GPa. Below this pressure the structure changes to another amorphous state and then a new crystal phase, at very close to atmospheric pressure. In the high-pressure amorphous state a strong A1-symmetric peak arising from the breathing mode of the SnI4 tetrahedral molecules splits into a doublet. This is interpreted in terms of pressure-induced dimerisation. The spectra for the liquid are also measured, for comparison with those for the amorphous state.