NMR INVESTIGATION OF THE QUATERNARY-INTERMETALLIC-COMPOUND SUPERCONDUCTOR YNI2B2C

Measurements of the B11 NMR spectrum, isotropic Knight shift (Ki), and spin-lattice relaxation rate (1/T1) in an unoriented powder sample of YNi2B2C are reported in the normal and the superconducting states. In the normal state, Ki varies linearly from (+5.70.7) × 10-4 at 300 K to (+4.90.7)×10-4 just above the superconducting transition temperature. The anisotropic Knight shift, if present, is substantially smaller than Ki. An anomalous increase in (T1T)-1 with decreasing temperature (T) is found in the normal state. From the behavior of the NMR linewidth in the superconducting state, the low-temperature limit (0)=(1085) nm is found for the penetration depth. At the superconducting transition, 1/T1 drops rapidly and no Hebel-Slichter peak is seen. © 1995 The American Physical Society.