M. Kuznietz et al., UCONIGE2, NONMAGNETIC SOLID-SOLUTION OF THE ANTIFERROMAGNETS UCO2GE2 AND UNI2GE2, Solid state communications, 90(2), 1994, pp. 93-97
The compounds UCo2Ge2 and UNi2Ge2 crystallize in the body-centered tet
ragonal ThCr2Si2-type structure (space group I4/mmm) and order with th
e AF-I antiferromagnetic structure [k=(0,0,1)]. Two polycrystalline sa
mples of UCoNiGe2, an intermediate solid solution of these compounds,
have been prepared under identical conditions and studied by x-ray and
neutron diffraction. Both samples crystallize in the lower-symmetry p
rimitive tetragonal CaBe2Ge2-type structure (space group P4/nmm). The
cobalt/nickel distribution in the M = (Co,Ni) planes in both samples i
s not random, with Co:Ni ratios of 36:64 in M2 planes, close to U plan
es, and 64:36 in doubly dense and distant M1 planes. Absence of magnet
ic order in UCoNiGe2 down to 10 K, is associated with its lower symmet
ry.