TY - JOUR
T1 - Cubic aluminum silicides RE8 Ru12Al49Si9(AlxSi12-x) (RE = Pr, Sm) from liquid aluminum. Empty (Si,Al)12 cuboctahedral clusters and assignment of the Al/Si distribution with neutron diffraction
AU - Sieve, B.
AU - Chen, X. Z.
AU - Henning, R.
AU - Brazis, P.
AU - Kannewurf, C. R.
AU - Cowen, J. A.
AU - Schultz, A. J.
AU - Kanatzidis, M. G.
PY - 2001
Y1 - 2001
N2 - Two new quaternary aluminum silicides, RE8Ru12Al49Si9 (AlxSi12-x) (x ∼ 4; RE = Pr, Sm), have been synthesized from Sm (or SM2O3), Pr, Ru, and Si in molten aluminum between 800 and 1000 °C in sealed fused silica tubes. Both compounds form black shiny crystals that are stable in air and NaOH. The Nd analog is also stable. The compounds crystallize in a new structural type. The structure, determined by single-crystal X-ray diffraction, is cubic, space group Pm3m with Z = 1, and has lattice parameters of a = 11.510(l) Å for Sm8Ru12Al49Si9 (AlxSi12-x) and a = 11.553(2) Å for Pr8Ru12Al49Si9 (AlxSi12-x (x ∼ 4). The structure consists of octahedral units of AlSi6 at the cell center, Si2RU4Al8 clusters, at each face center, SiAl8 cubes, at the middle of the cell edges, and unique (Al,Si)12 cuboctohedral clusters, at the cell corners. These structural units are connected to each other either by shared atoms, Al - Al bonds, or Al - bonds. The rare earth metal atoms fill the space between various structural units. The Al/Si distribution was verified by single-crystal neutron diffraction studies conducted on Pr8Ru12Al49Si9 (AlxSi12-x). Sm8Ru12Al49Si9 (AlxSi12-x) and Pr8Ru12-Al49Si9 (AlxSi12-x) show ferromagnetic ordering at Tc ∼10, and ∼20 K, respectively. A charge of 3+ can be assigned to the rare earth atoms while the Ru atoms are diamagnetic.
AB - Two new quaternary aluminum silicides, RE8Ru12Al49Si9 (AlxSi12-x) (x ∼ 4; RE = Pr, Sm), have been synthesized from Sm (or SM2O3), Pr, Ru, and Si in molten aluminum between 800 and 1000 °C in sealed fused silica tubes. Both compounds form black shiny crystals that are stable in air and NaOH. The Nd analog is also stable. The compounds crystallize in a new structural type. The structure, determined by single-crystal X-ray diffraction, is cubic, space group Pm3m with Z = 1, and has lattice parameters of a = 11.510(l) Å for Sm8Ru12Al49Si9 (AlxSi12-x) and a = 11.553(2) Å for Pr8Ru12Al49Si9 (AlxSi12-x (x ∼ 4). The structure consists of octahedral units of AlSi6 at the cell center, Si2RU4Al8 clusters, at each face center, SiAl8 cubes, at the middle of the cell edges, and unique (Al,Si)12 cuboctohedral clusters, at the cell corners. These structural units are connected to each other either by shared atoms, Al - Al bonds, or Al - bonds. The rare earth metal atoms fill the space between various structural units. The Al/Si distribution was verified by single-crystal neutron diffraction studies conducted on Pr8Ru12Al49Si9 (AlxSi12-x). Sm8Ru12Al49Si9 (AlxSi12-x) and Pr8Ru12-Al49Si9 (AlxSi12-x) show ferromagnetic ordering at Tc ∼10, and ∼20 K, respectively. A charge of 3+ can be assigned to the rare earth atoms while the Ru atoms are diamagnetic.
UR - http://www.scopus.com/inward/record.url?scp=0034826472&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034826472&partnerID=8YFLogxK
U2 - 10.1021/ja010135k
DO - 10.1021/ja010135k
M3 - Article
C2 - 11459482
AN - SCOPUS:0034826472
SN - 0002-7863
VL - 123
SP - 7040
EP - 7047
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 29
ER -