Pressure-Induced Superconductivity Emerging from Antiferromagnetic Phase in CeNiGe₃

The antiferromagnet CeNiGe 3 exhibits superconductivity under pressure. The Néel temperature initially increases with increasing pressure up to 3 GPa and then becomes zero at a critical pressure ( P C ) that is located at approximately 7 GPa. We found that superconductivity emerges from 1.7 GPa in the antiferromagnetic (AF) phase removed from P C . The superconductivity is realized in a wide pressure region including P C . The coefficient A in the resistivity and the upper critical field ( H c2 ) significantly change against pressure. A feature of CeNiGe 3 is that the moderate heavy fermion state in the AF phase induces superconductivity.