Single-crystal Brillouin spectroscopy with CO2 laser heating and variable q.
Single-crystal Brillouin spectroscopy with CO2 laser heating and variable q.
复制标题
采用 CO2 激光加热和可变 q 的单晶布里渊光谱。
DOI：
10.1063/1.4922634
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Gaohua Zhu
中科院分区：
文献类型：
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作者：
Jin S. Zhang;J. Bass;Gaohua Zhu
我们描述了一个集成了CO2激光加热和拉曼光谱功能的布里渊光谱系统。通过测量热样品发出的灰体热辐射来确定温度，系统响应相对于标准钨带灯进行校准。在2500 ± 150 K的高压下，利用激光加热布里渊散射测量了在金刚石压腔中压缩的液态水和冰的声速。在13GPa，1300 ± 200 K下，对San卡洛斯橄榄石的（111）面进行了激光加热布里渊测量。当KCl和KBr用作压力传输介质时，在激光加热期间，通过红宝石荧光测量的压力显示为在橄榄石样品上的压力的±0.5 GPa内。此外，该系统设计用于从前向散射（近0°散射角）到近后向散射（近141°）的连续可变散射角。这种新颖的设置使我们能够探测广泛的波矢量q，用于调查声子色散，例如，具有大晶胞的晶体（在数百nm的尺度上）。
We describe a Brillouin spectroscopy system integrated with CO2 laser-heating and Raman spectroscopic capabilities. Temperature is determined by measurements of the grey-body thermal radiation emitted by the hot sample, with the system response calibrated relative to a standard tungsten ribbon lamp. High-pressure laser-heating Brillouin scattering measurements of acoustic velocities on liquid water and ice compressed in a diamond-anvil cell were performed at temperatures up to 2500 ± 150 K at high pressure. Single-crystal laser-heating Brillouin measurements were made on the (111) plane of San Carlos olivine at ∼13 GPa, 1300 ± 200 K. The pressure as measured by ruby fluorescence is shown to be within ±0.5 GPa of the pressure on the olivine sample during laser heating when KCl and KBr are used as pressure-transmitting media. In addition, the system is designed for continuously variable scattering angles from forward scattering (near 0° scattering angle) up to near back scattering (∼141°). This novel setup allows us to probe a wide range of wave vectors q for investigation of phonon dispersion on, for example, crystals with large unit cells (on the scale of hundreds of nm).