Crystal structure and physical properties of UAuSi and UAu2
Abstract
UAuSi and UAu2 have been prepared by arc-melting of the elemental components and subsequent annealing. The crystal structure of UAuSi, which has been previously reported to crystallize in the TiNiSi-type structure, was determined from X-ray powder diffraction data: LiBaSi-type structure, Pm2, a= 419.5(2) pm, c= 397.2(2) pm, V= 0.0605 nm3, Z= 1 and RB(I)= 0.018. It is derived from the AlB2-type structure by an ordered arrangement of the gold and silicon atoms on the boron sites. The binary compound UAu2(AlB2-type) is confirmed. Magnetic susceptibility measurements indicate spin-glass behaviour and paramagnetism for UAuSi and UAu2, respectively. Both compounds are metallic conductors.