Superconducting state of layered superconductor kappa-(ET)(4)Hg2.89Br8 under magnetic field parallel to the conducting plane

The upper critical field of kappa-(ET)(4)Hg2.89Br8 was measured under a par allel magnetic field up to 24 T in the temperature region down to 0.5 K. Th e data obtained at 0.5 K indicate that the upper critical field tends to sa turate toward 0 K but exceeds the Pauli limit by more than two times. The a nisotropy of the upper critical field within the superconducting plane was not observed. The implication of the high upper critical field is discussed .