Synthesis, Structure, and Magnetoresistance of SmPd2Ga 2

Single crystals of a new ternary compound, SmPd2Ga2, have been synthesized by flux growth methods. This compound adopts a tetragonal space group 14/mmm, Z = 2, with lattice parameters a = 4.2170(3) Å and c = 10.4140(3) Å. 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 (dρ/dT \u3e 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