Nuclear magnetic resonance on oriented192Ir in Fe and Ni

The hyperfine interaction of¹⁹²Ir nuclei as dilute impurities in Fe and Ni has been investigated with NMR on oriented nuclei. With the use of highly dilute and pure alloys the line widths could be reduced so far that the quadrupole splitting of¹⁹²IrFe and¹⁹²IrNi could be resolved. Taking hyperfine anomalies into account the ground state nuclear moments of¹⁹²Ir are deduced as |μ|=1.924(10)μ _N andQ=2.36(ll) b. The hyperfine field of IrNi was investigated as a function of the Ir concentrationc between 0.01 at % and 5 at %. The dependence ofH _HF onc was found to be significantly smaller than that reported from Mössbauer effect measurements. Forc=0.01 at %H _HF=?454.7(2.3)kG is deduced. The resonance shift with an external magnetic field has been studied precisely, yieldingK=0.012(23) andK=0.026(12) for the Knight-shift of¹⁹²Ir in Fe and Ni, respectively.