Ultraviolet Luminescence from Defect Complexes in the Twin Boundaries of K-Feldspar
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- 作者：Luis Sá ; nchez-Muñ ; oz ; Javier Garcí ; a-Guinea ; Jesú ; s Sanz ; Virgilio Correcher ; and Antonio Delgado
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：July 11, 2006
- 年：2006
- 卷：18
- 期：14
- 页码：3336 - 3342
- 全文大小：280K
- 年卷期：v.18,no.14(July 11, 2006)
- ISSN：1520-5002
文摘
The ultraviolet (UV) emission at 290 nm has been studied by thermoluminescence (TL), cathodoluminescence (CL), and radioluminescence (RL) techniques in a natural K-feldspar with intermediatemicrocline X-ray diffraction pattern. Electron microprobe analyses (EMPA) give the chemical formulaK0.98Na0.02Al1.02Si2.98O8. An irregular submicroscopical twinning has been observed from transmissionelectron microscopy (TEM) images. Selected area electron diffraction (SAED) patterns along the [001]zone axis evidence the triclinic character of this feldspar (
* angle 
91
) and exhibit a double spotsplitting, associated with the presence of discrete twin-domains, interconnected by diffuse streaks. The29Si MAS NMR spectrum demonstrates that the appearance of this UV emission cannot be explained bydistinct T-O-T geometry of the local structure in comparison with other triclinic K-feldspars. The closeassociation between twinning and the UV band in the K-feldspar points to charge trapping and lightemissions from complexes of structural defects located at the twin-domain boundaries. The high-temperature slope of the TL glow curve follows a power law decay, suggesting possible trapping-detrapping dynamics related to cooperative phenomena inside the complexes.
* angle 91) and exhibit a double spotsplitting, associated with the presence of discrete twin-domains, interconnected by diffuse streaks. The29Si MAS NMR spectrum demonstrates that the appearance of this UV emission cannot be explained bydistinct T-O-T geometry of the local structure in comparison with other triclinic K-feldspars. The closeassociation between twinning and the UV band in the K-feldspar points to charge trapping and lightemissions from complexes of structural defects located at the twin-domain boundaries. The high-temperature slope of the TL glow curve follows a power law decay, suggesting possible trapping-detrapping dynamics related to cooperative phenomena inside the complexes.