Defects in sodalite-group minerals determined from X-ray-induced luminescence
Defects in sodalite-group minerals determined from X-ray-induced luminescence
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DOI：
10.1007/s00269-016-0816-7
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发表时间：
2016-07-01
影响因子：
1.4
通讯作者：
Maghrabi, Mufeed
中科院分区：
文献类型：
--
作者：
Finch, Adrian A.;Friis, Henrik;Maghrabi, Mufeed
在20 ~ 673 K温度范围内，收集了一组天然钠骨架硅酸盐（包括四种不同的方钠石变体和钙钛矿）在X射线辐照下的发光光谱。在这些样品中观察到的发射带的起源归因于F-中心（360 nm）、顺磁氧缺陷（400和450 nm）、S-2（-）离子（620 nm）和四面体Fe 3+（730 nm）。在黄色（550 nm）的发光初步归因于Mn 2+，和红色发光的富铬粉红色方钠石可能是来自Cr 3+激活。在60-120 K范围内，观察到所有矿物的发射中心的发光强度突然降低。由于它是所有钠长石族矿物所共有的，我们推断它是铝硅酸盐骨架的一个特征。方钠石发光具有来自框架上的取代的响应（例如，顺磁性氧缺陷，Fe 3+），其给出类似于其他框架硅酸盐（例如长石和石英）的方钠石性质。然而，含有阴离子（如F-中心，S-2（-）离子）的方钠石笼的存在赋予了类似于碱金属卤化物的额外性质。讨论了Fe ~（3+）与S ~（2-）偶联的可能性。方钠石组的整体发光行为可以理解为这些中心类型之间的竞争。
The luminescence spectra of a suite of natural sodium framework silicates including four different sodalite variants and tugtupite have been collected during X-ray irradiation as a function of temperature between 20 and 673 K. The origin of the emission bands observed in these samples is attributed to F-centres (360 nm), paramagnetic oxygen defects (400 and 450 nm), S-2 (-) ions (620 nm) and tetrahedral Fe3+ (730 nm). Luminescence in the yellow (550 nm) is tentatively attributed to Mn2+, and red luminescence in Cr-rich pink sodalite is possibly from Cr3+ activation. Sudden reduction in luminescence intensities of emission centres was observed for all minerals in the 60-120 K range. Since it is common to all the sodalite-group minerals, we infer it is a feature of the aluminosilicate framework. Sodalite luminescence has responses from substitutions on the framework (e.g. paramagnetic oxygen defects, Fe3+) which give sodalite properties akin to other framework silicates such as feldspar and quartz. However, the presence of the sodalite cage containing anions (such as F-centres, S-2 (-) ions) imparts additional properties akin to alkali halides. The possibility of coupling between Fe3+ and S-2 (-) is discussed. The overall luminescence behaviour of sodalite group can be understood in terms of competition between these centre types.