*2.3. Characterization*

The phase structure of the Fe-Cr-Zr alloy is identified using x-ray diffraction (XRD, Rigaku D/max-2400PC, Rigaku, Tokyo, Japan) with Cu K α radiation source. Microstructure of Fe-Cr-Zr alloy is characterized by FEI Inspect F50 scanning electron microscope (SEM) (FEI company, Oregon, America) and JEOL JEM-2100F transmission electron microscopy (TEM) (JEOL, Tokyo, Japan).

After oxidation tests in stagnant air and in oxygen-saturated stagnant liquid Pb-Bi eutectic, phase structure of oxide scale is identified using XRD. The surface and crosssectional morphologies of oxide scales are observed by SEM, and chemical compositions

are analyzed by energy-dispersive X-ray spectrometer (EDS) (Oxford Instruments, Oxford, UK). The element distribution analysis is conducted by Shimadzu EPMA-1610 electron probe microanalysis (EPMA) (Shimadzu, Kyoto, Japan). For preparing the cross-sectional samples after oxidation tests in stagnant air, the sample surface is protected by electroless Ni plating. The residual Pb-Bi eutectic on the surface of sample is retained after oxidation tests in oxygen-saturated stagnant liquid Pb-Bi eutectic to protect the oxide scale during the sample preparation process.
