Optical absorption and Mössbauer spectra of Fe, Ti silicate glasses
Optical absorption and Mössbauer spectra of Fe, Ti silicate glasses
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DOI：
10.1016/0022-3093(80)90482-2
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发表时间：
1980-03
影响因子：
3.5
通讯作者：
D. Nolet
中科院分区：
文献类型：
--
作者：
D. Nolet
在高温下测量了还原合成Fe、Ti硅酸盐玻璃的光学吸收光谱，并将结果与穆斯堡尔谱的信息相关联，以解决引起每个吸收的物种和配位环境的几个争议。Fe~(2+)八面体配位(95 0 0±30 0 cm−1，1.0 5μm)，四面体配位Fe~(2+)(5 30 0±2 0 0 cm−1，1 89μm)，八面体配位(17 70 0±30 0 cm−1，0 5 6μm)和Fe~(2+)→Ti4+电荷转移(CT)跃迁(2 4 0 0±30 0 cm−1，0 42μm)。几个氧-阳离子CT跃迁导致近紫外吸收边通常延伸到可见光区域。穆斯堡尔谱显示出与其他玻璃研究相同的不对称性，并被指定为八面体配位的Fe2+。这种不对称性被证明是由于多个重叠的微小变化的四极分裂偶而造成的。在这两组光谱中都没有发现两个可区分的八面体玻璃位置的证据。由于八面体和四面体消光系数之间存在两个数量级的差异，在光谱中观察到的玻璃中只有少量的四面体Fe2+。
Optical absorption spectra of reduced synthetic Fe, Ti silicate glasses were measured at elevated temperatures and results correlated with information from Mössbauer spectra in order to resolved several controversies concerning the species and coordination environment causing each absorption. Crystal field (CF) bands were resolved due to Fe2+in octahedral coordination (9500 ± 300 cm−1, 1.05μm), Fe2+in tetrahedral coordination (5300 ± 200 cm−1, 1.89μm), and Ti3+in octahedral coordination (17 700 ± 300 cm−1, 0.56μm) as well as the Fe2+→ Ti4+charge transfer (CT) transition (24 000 ± 300 cm−1, 0.42μm). Several oxygen-cation CT transitions contribute to the near-ultraviolet absorption edge usually extending into the visible region. Mössbauer spectra show asymmetry common to other glass studies and have been assigned to Fe2+in octahedral coordinations. The asymmetry is shown to be due to multiple overlapping doublets of slightly varying quadrupole splitting. No evidence of two distinguishable octahedral glass sites has been found in either set of spectra. Only minor amounts of tetrahedral Fe2+are present in the glasses, observed in the optical spectra due to the two orders of magnitude difference between octahedral and tetrahedral extinction coefficients.