Raman spectroscopic study of olivine-group minerals
Raman spectroscopic study of olivine-group minerals
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DOI：
10.2465/jmps.071015
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发表时间：
2008-04-01
影响因子：
0.7
通讯作者：
Enami, Masaki
中科院分区：
文献类型：
--
作者：
Mouri, Takashi;Enami, Masaki
用拉曼光谱研究了镁橄榄石-铁闪石系列天然样品和镁橄榄石-铁闪石系列天然样品的合成端元Mg_2SiO_4、Fe_2SiO_4、MnSiO_4和Co_2SiO_4的拉曼光谱。橄榄石族矿物的拉曼光谱具有Si-O不对称拉伸带(波数kappa(1))和Si-O对称拉伸带(kappa(2))两条强线的特征。M2位由非过渡元素占据的Mg_2SiO_4-Ca(Mg，Fe)SiO_4系列的kappa(1)和kappa(2)值分别在847 cm(-1)到857 cm(-1)和815 cm(-1)到825 cm(-1)之间变化，它们的omega(=kappa(1)-kappa(2))值在32 cm(-1)附近相当恒定。另一方面，过渡元素存在于M2点的铁闪石、钙辉石和其他橄榄石族矿物具有相当恒定的kappa(1)(836-839 cm(-1))值，而变化的kappa(2)(808-819 cm(-1))和omega(20-32 cm(-1))值。镁橄榄石-铁闪石系列的omega值随Mg#[=mg/(mg+Fe)]系统地增大，对确定其化学成分是有用的。
Synthetic end-members Mg2SiO4, Fe2SiO4, MnSiO4, and Co2SiO4 and natural samples of forsterite-fayalite series, tephroite and monticellite, are investigated using Raman spectroscopy. The Raman spectra of the olivine-group minerals have a characteristic set of two intense lines of the Si-O asymmetric stretching band (wavenumber kappa(1)) and Si-O symmetric stretching band (kappa(2)). The kappa(1) and kappa(2) values of the Mg2SiO4-Ca(Mg, Fe)SiO4 series, in which the M2 site is occupied by nontransition elements, vary from 847 cm(-1) to 857 cm(-1) and from 815 cm(-1) to 825 cm(-1), respectively, and their omega (= kappa(1) - kappa(2)) value is fairly constant around 32 cm(-1). On the other hand, fayalite, tephroite, and other olivine-group minerals in which transition elements exist in the M2 site have a fairly constant kappa(1) (836-839 cm(-1)) value and variable kappa(2) (808-819 cm(-1)) and omega (20-32 cm(-1)) values. The omega value of the forsterite-fayalite series systematically increases with Mg#[= Mg/(Mg + Fe)] and is useful for determining their chemical compositions.