Quasicrystalline tenfold symmetry order in boron compounds

We report the first quasicrystalline boride formed in a rapidly-solidified B₄₀Ti₁₂Ru₄₈ alloy, whose diffraction pattern clearly reveals a tenfold rotation axis of decagonal symmetry. The local structure appears to be significantly deviated from an ideal quasicrystal, but the long-range bond-orientationalorder restricted by linkages between the robust unit-clusters has successfully generated the apparent 10-fold-symmetric Bragg peaks. This may be attributed to an extreme case of random-tiling quasicrystals, which enable the occurrence of local tiling disorders to account for entropy.