  Single crystals of $R$Cd$_{3}$P$_{3}$ ($R$ = La and Ce) have been
investigated by magnetization, electrical resistivity, Hall coefficient, and
specific heat. Magnetization measurements of CeCd$_{3}$P$_{3}$ demonstrate
clear quasi-2D magnetic behavior. Electrical resistivity and Hall coefficient
measurements suggest that $R$Cd$_{3}$P$_{3}$ compounds are low carrier density
metallic systems, in strong contrast to an earlier study of polycrystalline
material. Specific heat and electrical resistivity measurements of
CeCd$_{3}$P$_{3}$ reveal a high temperature (structural) phase transition at
$T_{s} = 127$~K and antiferromagnetic ordering below $T_{N} = 0.41$~K. Upon
applying magnetic field in the easy-plane ($H {\parallel} ab$) the magnetic
ordering temperature increases to 0.43~K at $H \sim 15$~kOe, demonstrating
partial lifting of the magnetic frustration. The large electronic specific heat
persists in an unusually wide range of temperature above $T_{N}$, due to the
frustrated spins. The observation of conventional metallic behavior in the
electrical resistivity suggests that the $f$-electrons in CeCd$_{3}$P$_{3}$
undergo negligible hybridization with the conduction electrons. Thus,
CeCd$_{3}$P$_{3}$ may be a model system for exploring the complex interplay
between magnetic frustration and RKKY physics on a low carrier density Ce
triangular lattice.
