C. Kawamoto

K. Matsuda

S. Sunada

T. Muroga

T. Shinkawa

T. Tanaka

Y. Hishinuma

National Institute for Fusion Science (NIFS-Repository)

  An electrically insulating coating of an oxide ceramics is one of the attractive methods for reducing the magneto hydrodynamic (MHD) pressure drop which is a critical issue for liquid lithium fusion reactor blankets, and a ceramic coating for the inner wall would also be necessary to suppress the hydrogen permeation in a molten salt type blanket systems. [1] Recently, Hishinuma et al. have succeeded techniques for large area coating fabrication of Er2O3 layers by using the Metal Organic Chemical Vapor Deposition (MOCVD) process in gas phase [2]. In this study, Er2O3 coating layers with buffer layer of Y2O3 or CeO2 to reduce misfit between Er2O3 coating layer and a substrate of SUS steel substrate and to increase the total thickness of coated layers were fabricated. Their cross-sectioned TEM samples were fabricated by the focused ion beam (FIB) method to check their interfacial structures and their microstructures by XRD, SEM and TEM. Fig. 1 shows XRD obtained from 3 samples, which means Er2O3/ SUS, Er2O3 / Y2O3 / SUS and Er2O3 / CeO2 / SUS. samples. The lattice parameters of Er2O3 and Y2O3 are 1.0548 and 1.0487 nm, and similar to each other. It is difficult to distinguish to 2 phases, however, there are 2 peaks around 48 degree to correspond to 2 phases. Er2O3 and CeO2 phases can be detected by XRD. It is also clear what there are textures of <111> direction of Er2O3 on Er2O3 / Y2O3 / SUS, and <100> direction of Er2O3 on Er2O3 / CeO2 / SUS samples. Fig. 2 shows SEM images of surfaces for Er2O3 / Y2O3 / SUS and Er2O3 / CeO2 / SUS samples. It shows smooth surface morphology and homogeneous distribution of small crystal grains, although there are small surface reliefs. In the future work, the crystallographic orientation relationship between Er2O3, Y2O3 / CeO2 and SUS substrates will be clarified.  [Reference] [1] B. A. Pint, P. F. Tortorelli, A. Jankowski, J. Hayes, T. Muroga , A. Suzuki , O. I. Yeliseyeva , V. M. Chernov : J. Nucl. Mater, 329-333 (2004) 119-124. [2] Y. Hishinuma, T. Tanaka, T. Tanaka, T. Nagasaka, Y. Tasaki, A. Sagara, T. Muroga: Fusion Engineering and Design, 86 (2011) 2530-2533.  Fig. 1. XRD result for Er2O3/ Buffer (Y2O3,CeO2) / SUS sample. Fig. 2 SEM images of surfaces on Er2O3/Buffer (Y2O3,CeO2) / SUS samples. Left: Er2O3 / (Y2O3) / SUS, Right: Er2O3 / (CeO2) / SUS 339§20. Analysis of the Microstructure in the Oxide Double Coating Thin Layer for the Liquid BlanketMatsuda, K., Sunada, S., Kawamoto, C., Shinkawa, T. (Univ. Toyama),  Hishinuma, Y., Tanaka, T., Muroga, T.

Analysis of the Microstructure in the Oxide Double Coating Thin Layer for the Liquid Blanket

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