Morphological and structural study of crystals in black-to-brown glazes of Yaozhou ware (Song dynasty) using imaging and spectroscopic techniques

The Yaozhou kiln complex (Shaanxi, China) is a famous black-to-brown ceramic production center due to its significant volume of production, long manufacturing history (from Tang Dynasty Yuan Dynasty) and variety decorations. In this work, four representative types ware from the kilns were selected study morphology, structure distribution precipitated crystals in glazes using series imaging analytical techniques (optical microscopy, XRF, SEM-EDS, TEM-EDS, μRS UV–vis-IR). results show that rare metastable ε-Fe2O3 phase, already observed typical sauce glaze, was also detected other brown glaze decorations, such as light stripes on darker background or irregular spots black background. Cross-section analyses showed three well-separated layered crystalline lighter colors it has been noted Qilizhen kilns. Raman revealed contained third layer are varying nature: magnetite stripes. peak shifts line broadenings spectra investigated. They result Al, Ti Mg substitutions, which identified TEM-EDS. Such ionic substitutions would stabilize by increasing cationic disorder. addition, Mg-, Ca- Fe-rich spinel for first time wares.