Synthesis, Structure, and Magnetoresistance of SmPd2Ga

Single crystals of a new ternary compound, SmPd2Ga2, have been synthesized by flux growth methods. This compound adopts a tetragonal space group I4/mmm, Z = 2, with lattice parameters a = 4.2170(3) (angstrom) and c = 10.4140(3) (angstrom). The crystal structure is composed of layers of isolated Sm atoms and layers of PdGa4 edge-sharing tetrahedra alternating along the c-axis. The sample is metallic (d(rho)/dT > 0) with a weak temperature dependence above 100 K. This new material has physical properties similar to those of other Sm intermetallics and has, most notably, a large positive magnetoresistance at low temperatures. Magnetic measurements indicate that SmPd2Ga2 is ferromagnetic with Tc ~ 5 K.