### Abstract

Variation of superconducting transition temperature Tc for the pseudoternary Sr(T1-xT'x)2Ge2 layer systems (T, T' Co, Ni, Rh, Pd; 0 ≤ x ≤ 1) are reported. For the system Sr(Pd1-xRhx)2Ge2, Tc decreases from 3.12 K for x 0, to 2.92 K for x 0.1, to 2.50 K for x 0.2, and extrapolated to 0 K for x 0.65. No Tc is expected for SrRh2Ge2. For the system Sr(Pd1-xCox)2Ge2, Tc decreases sharply to 2.80 K for x 0.01, 2.58 K for x 0.03, and extrapolates to 0 K for x 0.15. No Tc is also expected for SrCo2Ge2. In these systems, stronger Tc suppression for Co(3d^{7}) and Rh(4d^{7}) were due to lower density of states in dxz,yz bands with one less conduction electron per transition metal. Weaker Tc suppression for isoelectronic Ni is due to shift from Pd-4d^{8} to Ni-3d^{8} band. Tc decreases monotonically from 3.12 K for SrPd2Ge2 to 0.92 K for SrNi2Ge2. The lower Tc of the present electron-overdoped (nd^{7} or nd^{8}) compounds are due to dispersive 3D-like ndxz,yz conduction bands with weaker electron correlation, as compared to the less-electron-doped (3d^{6.1}) 22 K superconductor BaFe1.8Co0.2As2 or the hole-doped (3d^{5.9}) 38 K superconductor Ba0.6K0.4Fe2As2 with additional less dispersive 2D-like 3dxy band contribution and stronger electron correlation.

Original language | English |
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Article number | 012131 |

Journal | Journal of Physics: Conference Series |

Volume | 391 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2012 Jan 1 |

Event | International Conference on Strongly Correlated Electron Systems, SCES 2011 - Cambridge, United Kingdom Duration: 2011 Aug 29 → 2011 Sep 3 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

_{1-x}T'

_{x})

_{2}Ge

_{2}(T, T' = transition metals).

*Journal of Physics: Conference Series*,

*391*(1), [012131]. https://doi.org/10.1088/1742-6596/391/1/012131