氧化铁及分相结构对钧窑蓝色系釉的呈色作用

钧窑大部分产品的基本釉色之一是各种浓淡不一的蓝色乳光釉。为了探讨釉层呈乳光蓝色及其深浅的原因,利用聚焦离子束、场发射扫描电镜(配备EDS)、高分辨率透射电镜(配备EDS)、穆斯堡尔谱仪以及紫外可见分光光度计等手段,对7片出土于河南禹县钧窑遗址的具有深浅不一蓝色釉层的残片样品进行科学分析。结果发现,钧窑蓝色系釉层的主要着色剂为Fe2+,其含量的增加能够使釉面蓝色饱和度增大;此外,釉层中存在着大小不一的分相液滴,小液滴尺寸增大,能够使蓝色釉面颜色偏绿、明度提高。即钧窑蓝色乳光釉的呈色是化学成分和显微结构的共同作用,也是对可见光散射和吸收共同作用的结果。

The coloring function of iron oxide and phase separation in the blue glaze of Jun Ware

The main color in the glaze of most Jun ware is a large range of blues. In order to investigate the origin of the blue glaze color and its change in hue, seven pieces of ancient Jun ware were analyzed using scanning electron microscopy, transmission electron microscopy, Mossbauer spectroscopy and Ultraviolet-visible spectrometry. The results show that Fe²⁺ is the dominant colorant in the Jun glaze and that the higher the Fe²⁺ concentration, the higher the saturation of the blue color. Phase separation is also observed in the Jun ware glazes. The big droplets endow the glaze with a greenish hue with higher luminosity, which finally weakens the iron blue color. The blue color of Jun ware glaze is a result of both its chemical composition and the microstructure, in other words, a consequence of both the absorption and scattering of the light.