Ilvaite: A study of temperature dependent electron delocalization by the mössbauer effect
Ilvaite: A study of temperature dependent electron delocalization by the mössbauer effect
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Ilvaite：穆斯堡尔效应对温度依赖性电子离域的研究
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
R. Burns
中科院分区：
文献类型：
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作者：
D. Nolet;R. Burns
The mixed valence iron silicate ilvaite, CaFe22+Fe3+Si2O8(OH), displays electron delocalization associated with Fe2+→Fe3+ charge transfer as observed by Mössbauer spectroscopy. Previous studies report the observation of an ‘electron hopping phenomenon’ with resolution of discrete valence states below 320 K. Mössbauer spectra of a suite of naturally occurring ilvaites were recorded over a temperature range, 80 K to 575 K. Five quadrupole doublets were resolved by computer fitting and assigned to Fe2+(A), Fe2+(B), Fe3+(A), and Fe2+(A)→Fe3+(A)‖c and ⊥c. Contrary to prior work, doublets associated with electron delocalization are resolved at 80 K and preclude the use of a Verwey-type order-disorder model. We propose a thermal activation model and discuss its criteria from molecular orbital and mineralogical viewpoints.
