Single crystals of the new ternary compound Ce2Ga12Pt were prepared by the
self-flux technique. The crystal structure with the space group P4/nbm was
established from single-crystal X-ray diffraction data and presents a
derivative of the LaGa6Ni0.6 prototype. Magnetic susceptibility measurements
show Curie-Weiss behaviour due to local Ce^3+ moments. At high temperatures,
the magnetic anisotropy is dominated by the crystal-electric-field (CEF) effect
with the easy axis along the crystallographic c direction. Ce2Ga12Pt undergoes
two antiferromagnetic phase transitions at T_N,1 = 7.3K and T_N,2 = 5.5K and
presents several metamagnetic transitions for the magnetic field along c.
Specific-heat measurements prove the bulk nature of these magnetic transitions
and reveal a doublet CEF ground state. The 4f contribution to the resistivity
shows a broad maximum at T_max ~ 85K due to Kondo scattering off the CEF ground
state and excited levels.Comment: 12 pages, accepted in J. Phys.: Condens. Matte