俯冲带温度条件下橄榄石中硅氧四面体的非谐振动:透射红外光谱研究

CORC > 北京大学 > 地球与空间科学学院

	俯冲带温度条件下橄榄石中硅氧四面体的非谐振动:透射红外光谱研究; Anharmonie vibration of the SiO4 tetrahedron in olivine at temperatures in the subduction zone: An infrared absorbance spectroscopic study
	王霏 ; 刘曦 ; 郑海飞 ; 张立飞
刊名	岩石学报
	2015
关键词	非谐振动非谐系数橄榄石红外透射光谱温度的影响 Anharmonic vibration Anharmonicity coefficient Olivine Infrared transmission spectroscopy Effect of temperature SINGLE-CRYSTAL FORSTERITE UPPER-MANTLE RAMAN-SCATTERING LATTICE-DYNAMICS TRANSITION ZONE HIGH-PRESSURE SPECTRA MINERALS FAYALITE MG2SIO4
英文摘要	橄榄石既是上地幔的主要矿物,又是俯冲板块的主要矿物。在正常地幔温度条件下,橄榄石中原子之间的振动是非谐振动,这已成为学界共识;然而,对于俯冲带的较低温情况,橄榄石中原子之间的振动的非谐性是否重要,目前还没有比较一致的结论。本研究利用透射红外光谱的方法,系统研究了室温下不同厚度橄榄石中硅氧四面体的红外光谱特征,并着重对其在2100~1500cm~(-1)区域形成的二倍频峰/合频峰进行了指认。在此基础上,本研究通过采集不同温度下的透射红外光谱数据(最高温度达约450℃),确立了橄榄石中硅氧四面体的相应基频峰及二倍频峰峰位对温度的依赖性,进而得出其相应红外振动的非谐系数(X)随温度(T)的变化关系,具体为:X_(838) =6.37(2) ×10~(-7) × T + 0. 0014( 1)及X_(993) =7.86(3) ×10~(-7) ×T + 0.0015(1),其中温度的单位为℃。外推到600℃时,有X_(838) =0.0018( 1 )及X_(993)=0.0020(2)。这些结果表明,在俯冲带的较低温条件下,橄榄石中硅氧四面体的内部振动的非谐性可能不重要。; Olivine is not only the dominant mineral in the upper mantle of the Earth, but also the major mineral in the subducted slab. It is generally accepted that the atom groups in olivine vibrate in an anharmonic manner at normal mantle temperatures. How they behave at the low temperatures typical in a subduction zone, however, is unclear. In this study, we systematically investigated the IR features of some doubly polished olivine thin sections with different thicknesses using infrared transmission spectroscopy, especially focusing on the overtone/combination bands in the 2100 similar to 1500cm(-1) region. With the IR data collected from room temperature to about 450 degrees C, we obtained the relationships between the anharmonicity coefficient (chi) and temperature for two characteristic IR bands of the SiO4 tetrahedra: the equations are chi(838) =6.37(2) x 10(-7) x T + 0. 0014(1) and chi(993) =7.86(3) x 10(-7) x T + 0. 0015(1), with T in degrees C. When extrapolated to 600 degrees C, these equations produce chi(838) = 0. 0018 (1) and chi(993) = 0. 0020 (2), which presumably indicate a negligible role of the anharmonic behavior for the SiO4 tetrahedra in olivine at the low temperatures in the subduction zone.; 国家自然科学基金项目; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); wangfei1049@gmail.com; xi.liu@pku.edu.cn; 7; 1891-1900; 31
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/414672]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	王霏,刘曦,郑海飞,等. 俯冲带温度条件下橄榄石中硅氧四面体的非谐振动:透射红外光谱研究, Anharmonie vibration of the SiO4 tetrahedron in olivine at temperatures in the subduction zone: An infrared absorbance spectroscopic study[J]. 岩石学报,2015.
APA	王霏,刘曦,郑海飞,&张立飞.(2015).俯冲带温度条件下橄榄石中硅氧四面体的非谐振动:透射红外光谱研究.岩石学报.
MLA	王霏,et al."俯冲带温度条件下橄榄石中硅氧四面体的非谐振动:透射红外光谱研究".岩石学报 (2015).