XRS-220084

The physical structure information of glaze layers was studied by non-destructiveswept source optical coherence tomography (OCT, HSL-2100, Santec, Aichi, Japan). The OCT is a new imaging technology based on confocal microscopy and Michelsoninterference principle, providing a quick view of internal structure and uniformity ofsamples[19,20]. Recently, this technology has been successfully applied in the ancientChinese porcelains to study the glaze features[21,22]. The experiments were carried outin sweep mode. The central wavelength is around 1315-1340 nm. The transverse andlongitudinal resolution is 2.4 μm/pixel and 5.3 μm/pixel, respectively. Besides, therefractive index of silicate material is 1.5, and imaging depth is more than 2 mm. Portable energy dispersive X-ray fluorescence spectrometer (PXRF, OURSTEX100FA, OURSTEX, Osaka, Japan) was applied for the chemical composition analysis. The XRF instrument consists of four separate parts: an X-ray spectrometer, a compactdigital processing unit, a compact power unit including the high-voltage transformerand power supply, a vacuum sample chamber. The PXRF technology uses palladium(Pd) as excitation tube and works continuously in three different modes, effectivelymeasuring the major elements, trace elements and weight elements, respectively. Thecorresponding voltage and current are 15 kV, 40 kV, 40 kV and 1 mA, 0.5 mA, 1 mA. This spectrometer typically used a silicon drift detector (SDD) with active area of 5mm2 equipped with one polymer window (MOXTEK AP 3.3 film), which can providesuperior X-ray transmission in the low-energy range down to Be-Kα. Combined withthe introduction of a low-vacuum sample chamber, the content of light elements (suchas Na and Mg) can be acquired. The X-ray beam spot irradiated at the sample is about2.5 mm in diameter. The spectrometer is also equipped with a charged coupled device(CCD) system, which is beneficial to confirm the area to be measured. For this XRF instrument, standard samples (NIST 1411 and BR CH4), purchasedfrom the Breitlander Eichproben und Labomaterial GmbH, Germany, were employedfor checking the precision and accuracy. A set of standard samples (22), purchasedfrom the Breitlander Eichproben und Labomaterial GmbH, Germany, containing mostinterested major and trace elements in silicate materials were applied for making thecalibration curves for the porcelain glaze. Meanwhile, a set of standard samples (13), provided by the Shanghai Institute of Ceramics, Chinese Academy of Sciences, China, were used to make the calibration curves for the porcelain body. More details can befound in the published articles[23-26]. It should be noted that spectral line overlaps alsoexist between Fe Kβ (7.06 keV) and Co Kα (6.925 keV), Pb Mα (2.3426 keV) and SKα (2.3075 keV). But for Jian wares, their porcelain glaze and body contain almost noCo, Pb and S. Thus, in this work, we needn’t to take the spectral line overlaps intoconsideration. Similar equipment had already been applied successfully in chemicalcomposition analysis of ancient porcelains and ceramics[3,4,11]. X-ray diffractometer (XRD, D/max 2550V, Rigaku, Tokyo, Japan) with filteredCu Kα radiation (40 kV, 40 mA) was performed on glaze surface to identify the phaseconstituents (scanning speed: 2° min-1; scanning area: 20-80°). To effectively acquirephase information on crystals and base glazes, Raman spectra were collected at roomtemperature by confocal micro-Raman spectrometer (LRS, LabRAM XploRA, Horiba, Palaiseau, France) with 532 nm laser excitation, and its power was 300 mW. Optical microscopy observation was carried out by optical microscope equippedwith an ultra-depth-of-field system (OM, VHX-50000, Keyence, Osaka, Japan). Themorphological and elemental analyses of glaze (both the surfaces and cross-sections)were conducted by scanning electron microscope (SEM) fixed with energy-dispersiveX-ray spectrometer (EDS) operated in back scattered electron image mode (TM3000, HITACHI, Tokyo,