High-pressure synthesis of light lanthanide dodecaborides and valence fluctuation of cerium

High-pressure synthesis methods offer an effective way to incorporate larger cations in the truncated octahedron cage in RB₁₂. The valence fluctuation of cerium reduces the cationic radius and thus reduces the formation pressure.  The cage structure internally filling of valence shell of lanthanide ions exhibits a variety of physical properties in RB₁₂.　The synthesis of the unexplored lanthanide dodecaborides may open a way for the findings of their peculiar physical properties. Dr. Hitoshi YUSA (NIMS RFMC HPG), Prof. Fumitohi IGA (Ibaraki Univ.) and Dr. Hiroshi FUJIHISA (AIST) contributed this article.