CHEMICAL PRESSURE EFFECTS ON THE CRYSTALLOGRAPHIC AND MAGNETIC-BEHAVIOR OF CENIGA3

The results of x-ray diffraction, magnetic susceptibility (chi), heat- capacity (C), and electrical resistivity (rho) measurements on the all oys Ce1-xYxNiGa3 (x=0.0, 0.2, and 0.8) are reported. While CeNiGa3 cry stallizes in the CePtGa3-type orthorhombic structure under our prepara tive conditions, the orthorhombicity diminishes with increasing Y conc entration resulting in the BaAl4-type tetragonal structure for x=0.8. The C data show the existence of a magnetic transition for x=0.0 and 0 .2 below 2.2 K. The features due to an interplay of the Kondo effect, crystal-field effect, and magnetic ordering are observed in the experi mental data.