Raman spectroscopy study of manganese oxides: Tunnel structures
Raman spectroscopy study of manganese oxides: Tunnel structures
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DOI：
10.2138/am-2020-7390
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发表时间：
2020-08-01
影响因子：
3.1
通讯作者：
Heaney, Peter J.
中科院分区：
文献类型：
--
作者：
Post, Jeffrey E.;McKeown, David A.;Heaney, Peter J.
拉曼光谱收集了广泛的一组充分表征的隧道结构锰氧化物矿物物种采用一系列的数据收集条件。使用各种激光波长，如785，633和532 nm，在低功率水平（30-500 μ W），以及这里提出的标准光谱的综合数据库，它通常是可能的区分和识别各种隧道结构的锰氧化物矿物。拉曼模式相对强度可以作为相对于入射激光偏振方向的晶体取向以及激光波长的函数而显著变化。因此，当使用包括针对不同晶体取向和不同激光波长收集的多个光谱的标准数据库时，相位识别成功率得到提高。对于奥朗德族矿物，在630 cm（-1）附近的拉曼模频率与八面体Mn位中Mn ~（3+）的分数呈强线性相关。通过这里提供的全面的拉曼数据库（以及在线提供的补充材料1），并使用适当的数据收集条件，微拉曼是一个强大的工具，用于识别和表征来自不同自然环境（包括其他星球）的生物和非生物氧化锰相。
Raman spectra were collected for an extensive set of well-characterized tunnel-structure Mn oxide mineral species employing a range of data collection conditions. Using various laser wavelengths, such as 785, 633, and 532 nm at low power levels (30-500 mu W), as well as the comprehensive database of standard spectra presented here, it is generally possible to distinguish and identify the various tunnel structure Mn oxide minerals. The Raman mode relative intensities can vary significantly as a function of crystal orientation relative to the incident laser light polarization direction as well as laser light wavelength. Consequently, phase identification success is enhanced when using a standards database that includes multiple spectra collected for different crystal orientations and with different laser light wavelengths. For the hollandite-group minerals, the frequency of the Raman mode near 630 cm(-1) shows a strong linear correlation with the fraction of Mn3+ in the octahedral Mn sites. With the comprehensive Raman database of well-characterized Mn oxide standards provided here (and available online as Supplemental Materials1), and use of appropriate data collection conditions, micro-Raman is a powerful tool for identification and characterization of biotic and abiotic Mn oxide phases from diverse natural settings, including on other planets.