Orthorhombic Yb2Co3Ga9 has a Pauli paramagnetic, moderate heavy-fermion gro
und state. Tn the isotypic new compound Yb2Co3Al9, Yb ions order magnetical
ly near 1.2 K; with a possible modest Kondo coupling with the conduction ba
nd electrons. (C) 1999 Elsevier Science B.V. All rights reserved.