• unknown: Sc4.5−xB57−y+zC3.5−z; boron-rich scandium borocarbide; floating zone crystal growth; single-crystal structure analysis; orthorhombic structure; B12 icosahedron
• unknown: Sc4.5−xB57−y+zC3.5−z; boron-rich scandium borocarbide; floating zone crystal growth; single-crystal structure analysis; orthorhombic structure; B12 icosahedron
• unknown: Sc4.5−xB57−y+zC3.5−z; boron-rich scandium borocarbide; floating zone crystal growth; single-crystal structure analysis; orthorhombic structure; B12 icosahedron

• NIMS Digital Library
• NIMS Digital Library ScBC orthoforDL.pdf (3.36 MB) (NIMS only)

A novel ternary boron-rich scandium borocarbide Sc4.5−xB57−y+zC3.5−z (x=0.27, y=1.1, z=0.2) was found. Single crystals were obtained by the floating zone method by adding a small amount of Si. Single-crystal structure analysis revealed that the compound has an orthorhombic structure with lattice constants of a=1.73040(6), b=1.60738(6) and c=1.44829(6) nm and space group Pbam (No. 55). The crystal composition ScB13.3C0.78Si0.008 calculated from the structure analysis agreed with the measured composition of ScB12.9C0.72Si0.004. The orthorhombic crystal structure is a new structure type of boron-rich borides and there are six structurally independent B12 icosahedra I1—I6, one B8/B9 polyhedron and nine bridging sites all which interconnect each other to form a three-dimensional boron framework. The main structural feature of the boron framework structure can be understood as a layer structure where two kinds of boron icosahedron network layer L1 and L2 stack each other along the c-axis. There are seven structurally independent Sc sites in the open spaces between the boron icosahedron network layers.