YbFeGe, a new structure type of equiatomic ternary germanides

The crystal structure of the new ternary germanide YbFeGe, space group C2/m (N12), a=10.607(6) Angstrom, b=3.904(2) Angstrom, c=6.715(3) Angstrom, bet a =127.58(1)degrees, Z=4, V=220.35 Angstrom, rho =9.088 g cm(-3), mu=61.67 mm(-1) was refined to R=0.0313, wR2=0.0705 from single crystal X-ray diffra ction data. This is the first representative of a new structure type (str. type) of intermetallic compounds. The formation and crystal structure for t his compound were confirmed from X-ray powder diffraction: a=10.5755(5) Ang strom, b=3.9034(3) Angstrom, c=6.7117(4) Angstrom, beta =127.68 degrees. An isotypic YbMnGe compound was observed: YbFeGe str. type, C2/m space group (sp. gr.), a=10.5966(4) Angstrom, b=3.9014(2) Angstrom, c=6.7782(3) Angstro m, beta =127.42 degrees. The crystal structures for the YbCoGe compound (Ti NiSi str. type, Pnma sp. gr., a=6.7168(4) Angstrom, b=4.0392(2) Angstrom, c =7.2684(4) Angstrom) and YbMn2Ge2 compound (CeGa2Al2 str. type, 14/mmm sp. gr., a=4.0334(5) Angstrom, c=10.0334(7) Angstrom) are reported for the firs t time. (C) 2000 Elsevier Science B.V. All rights reserved.