Nuclear magnetic resonance of oriented 196Au, 198Au, and 200Aum in Ni

The effective hyperfine splitting frequencies ν¯ of ¹⁹⁶Au (I^π=2^-, T₁₂=6.2 d), ¹⁹⁸Au (I^π=2^-, T₁₂=2.7 d), and ²⁰⁰Au^m (I^π=12^-, T₁₂=18.7 h) in nickel at a temperature of ~10 mK were measured with nuclear magnetic resonance on oriented nuclei to be 59.65(6) MHz, 60.06(5) MHz, and 99.1(3) MHz, respectively. All frequencies are considerably larger than those known from previous nuclear magnetic resonance on oriented nuclei measurements. Our results show that the noncontact contribution to the hyperfine field of AuNi is smaller than deduced before. The magnetic moment of ²⁰⁰Au^m [configuration |(π112^-)(ν132⁺)>_12^-], | μ |=5.90(9)μ_N, fits well into the systematics of magnetic moments of 12^- isomers in this mass region.