Nuclear magnetic relaxation in C14 YMn2

C14 YMn2synthesized under high pressure was investigated by NMR technique. It was found that C14 YMn2is paramagnetic down to the lowest temperature, in contrast with the antiferromagnetic ground state found for C15 YMn2. The nuclear spin-lattice relaxation rate of 55Mn in C14 YMn2increases rapidly at low temperatures and tends to saturate above about 50 K, indicating that strong spin fluctuations with antiferromagnetic correlation are rapidly induced on Mn sites by the temperature.