Split Fermi Surface Properties of LaTGe_3 (T: Transition Metal) and PrCoGe_3 with the Non-centrosymmetric Crystal Structure(Condensed matter: electronic structure and electrical, magnetic, and optical properties)

概要

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We succeeded in growing single crystals of LaTGe_3 (T: Fe, Co, Rh, Ir) and PrCoGe_3 with the non-centrosymmetric tetragonal crystal structure, and studied the split Fermi surface properties and the magnitude of the antisymmetric spin-orbit interaction 2|αp_⊥|. The 2|αp_⊥| value is found to vary when LaTGe_3 is changed from T=Co, Rh to Ir, but remains unchanged in LaIrX_3 from X=Si to Ge. It is found that this 2|αp_⊥| value is large in LaIrSi_3 and LaIrGe_3: 2|αp_⊥|=460K in LaCoGe_3, 510K in LaRhGe_3, 1100K in LaIrSi_3, and 1090K in LaIrGe_3 for the main outer orbits named a of bands 69 and 70 electron Fermi surfaces, for example. This is due to the large effective atomic number of Ir and a large distribution of the radial wave function of Ir-5d electrons close to the nuclear center, compared with those of Co and Rh. In the case of a paramagnet PrCoGe_3 and LaFeGe_3 with the relatively large cyclotron mass, the corresponding 2|αp_⊥| value is found to become small: 2|αp_⊥|=280 and 460K for main orbits α in PrCoGe_3 and LaCoGe_3, respectively, and 130K for main orbits in LaFeGe_3.
社団法人日本物理学会の論文
2008-06-15