Detection of a P-induced liquid ⇌ solid-phase transformation using multiple acoustic transducers in a multi-anvil apparatus
Detection of a P-induced liquid ⇌ solid-phase transformation using multiple acoustic transducers in a multi-anvil apparatus
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DOI：
10.1080/08957959.2015.1035715
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发表时间：
2015-04
影响因子：
2
通讯作者：
T. Officer;R. Secco
中科院分区：
文献类型：
--
作者：
T. Officer;R. Secco
本文报道了一种通过测量纵向声波传播时间随压力的变化来检测和测量多砧仪器中相变的技术。该系统测量脉冲超声波信号通过高压组件的时间，该组件的中心有样品。当相变从液体变为固体时，由于样品中速度的固有增加和振幅阈值触发与波形到达之间的延迟缩短，行程时间突然减少。作为概念的证明，结果显示了汞，因为它在室温下经历压力诱导的液体+固体转变。我们提出，在其他原位探测技术无法轻易用于提供状态变化信息的情况下，这种非破坏性技术可能是有价值的，也可能用于研究高压下的转变动力学。
A technique for detecting and measuring phase transitions in a multi-anvil apparatus by measuring the change in travel time for a longitudinal sound wave as a function of pressure is reported. The system measures the time for pulsed ultrasonic signals to travel through a high pressure assembly with a sample in the center. Upon phase change from liquid to solid, the travel time shows an abrupt decrease due to the intrinsic increase in velocity in the sample and a reduced delay between the triggering of an amplitude threshold and the arrival of the waveform. As a proof of concept, results are shown for mercury as it undergoes pressure-induced liquid ⇌ solid transitions at room temperature. We propose that this non-destructive technique may be valuable in situations where other in situ probing techniques cannot be readily used to provide information about changes of state and potentially to study transition kinetics at high pressures as well.