Williams Willa M, Macaluso Robin T, Moldovan M, Young D P, Chan Julia Y
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Inorg Chem. 2003 Nov 3;42(22):7315-8. doi: 10.1021/ic034660r.
Single crystals of a new ternary compound, SmPd(2)Ga(2), 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) A and c = 10.4140(3) A. The crystal structure is composed of layers of isolated Sm atoms and layers of PdGa(4) 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 SmPd(2)Ga(2) is ferromagnetic with T(c) approximately 5 K.
通过助熔剂生长法合成了一种新型三元化合物SmPd₂Ga₂的单晶。该化合物属于四方空间群I4/mmm，Z = 2，晶格参数a = 4.2170(3) Å，c = 10.4140(3) Å。晶体结构由沿c轴交替排列的孤立Sm原子层和PdGa₄边共享四面体层组成。该样品是金属性的（dρ/dT > 0），在100 K以上具有较弱的温度依赖性。这种新材料具有与其他Sm金属间化合物相似的物理性质，最显著的是在低温下具有较大的正磁阻。磁性测量表明SmPd₂Ga₂是铁磁性的，居里温度T(c)约为5 K。
