Crystal structures of cobalt aluminum silicide, Co19+xAl43+ySi12-y (x = -0.14, y = 0.14; x = 0.49, y = -0.49), the ϒ phase in the Co-Al-Si system

Abstract Al43.14Co18.86Si11.86, monoclinic, C12/c1 (no. 15), a = 20.010(2) Å, b = 19.1498(7) Å, c = 12.8227(8) Å, β = 123.56(1)°, V = 4094.6 Å3, Z = 4, Rgt(F) = 0.035, wRref(F2) = 0.079, T = 293 K. Al42.51Co19.49Si12.49, monoclinic, C12/c1 (no. 15), a = 20.025(2) Å, b = 19.173(2) Å, c = 12.835(1) Å, β = 123.63(1)°, V = 4103.2 Å3, Z = 4, Rgt(F) = 0.044, wRref(F2) = 0.108, T = 293 K.