Unconventional superconductivity and magnetism in CePt3Si1-xGexCePt3Si1-xGex

CePt3SiCePt3Si is a novel ternary compound exhibiting antiferromagnetic order at TN≈2.2K and superconductivity (SC) at Tc≈0.75K. Large values of Hc2′≈-8.5T/K and Hc2(0)≈5T indicate Cooper pairs formed out of heavy quasiparticles. The mass enhancement originates from Kondo interaction with a characteristic temperature TK≈8K. NMR and μSRμSR measurements evidence coexistence of SC and long-range magnetic order on a microscopic scale. Moreover, CePt3SiCePt3Si is the first heavy fermion SC without an inversion symmetry. This gives rise to a novel type of NMR relaxation rate 1/T11/T1 which is very unique and never reported before for other heavy fermion superconductors. Studies of Si/Ge substitution allow us to establish a phase diagram.