Superconductivity in Exchange-Enhanced Paramagnetic Compound Ti0.5+xCo0.5-x

TiCo, a d-band metal, is known to be an exchange-enhanced itinerant paramagnet. We measured the dc susceptibility of polycrystalline Ti_0.5+xCo_0.5-x with small x over the temperature range of 1.7 to 300 K. In order to study superconductivity, the ac susceptibility of this compound was also measured down to 14 mK. We observed superconductivity in this system, whose superconducting transition temperature was approximately 35 mK for Ti_0.510Co_0.490.