黄土着色天青釉的还原状态及釉色分析

Analysis of the Reduction State and Glaze Color of Loess Colored Sky-green Celadon

以铜川地区黄土作为着色剂,以磷酸钙为磷元素来源,进行了仿耀州五代天青釉的制备研究。利用色度仪,XRD、Raman、UV-vis-NIR、XPS和SEM等测试手段,研究了黄土加入量对釉色、物相、显微结构以及铁元素价态的影响,分析了其呈色机理,并与古代样品进行了对比。结果表明:随着黄土含量的增加,釉面的亮度值(L*)先减小后增大,黄蓝值(b*)先增大后减小。同时,釉熔体黏度减小,气泡和分相液滴的尺寸增大,硅氧四面体(Qn)桥氧离子数减小。铁的含量的增多,使Fe^(2+)和Fe^(3+)的原子比从54.37/45.63减小至41.74/58.26,釉色由蓝白向蓝青到青绿色发展。釉内的晶体使入射光线产生固相乳浊,同时短程有序的分相结构产生光子非晶结构色,修饰了铁的化学色。在黄土含量达到20%~30%时,获得了理想的仿耀州窑五代天青釉效果。

Using the loess in Tongchuan as the coloring agent and calcium phosphate as the source of phosphorus,the preparation research of imitating Five dynasty sky-green glaze of Yaozhou kiln was carried out.Adoping colorimeter,XRD,Raman,UV-vis-NIR,XPS and SEM and other test methods,the influence of the amount of loess on the glaze color,phase,microstructure and iron valence was studied,its coloring mechanism was analyzed,and it was compared with ancient samples.The results showed that with the increase of loess content,the brightness value (L*) of the glaze surface first decreased and then increased,and the yellow-blue value (b*) first increased and then decreased.At the same time,the viscosity of the glaze melt decreases,the size of bubbles and phase-separated droplets increases,and the number of oxygen ions bridged by the silicon-oxygen tetrahedron (Qn) decreases.The increase in iron content reduces the ratio of Fe^(2+)and Fe^(3+)from 54.37/45.63 to 41.74/58.26,and the glaze color develops from bluewhite to blue-green to blue-green.The crystals in the glaze make the incident light produce solid phase opalescence,and the short-range orderly phase-separated structure produces a photonic amorphous structure color,which modifies the chemical color of iron.When the loess content reaches 20%~30%,the ideal effect of imitating the Five dynasty sky-green glaze of Yaozhou kiln is obtainedd.