Simultaneous Determination of the Magnetic Moments of 6Li and 7Li Nuclei Using an NMR Spectrometer

Abstract

The ratio of NMR frequencies of lithium isotopes f(7Li)/f(6Li) = 2.6409061846(13) was determined with an error of 4.9·10–10. The use of a nuclear magnetic resonance spectrometer operating in the mode of simultaneous registration of signals from two nuclei to obtain data allowed the random and systematic errors in the measurement results to be reduced by an order of magnitude. The ratio of the resonant frequencies of water protons and 7Li ions was determined: f(H2O)/f(7Li) = 2.557100473(9) with an error of 3.5·10–9 for solutions with an extremely low concentration of LiOH*H2O salt in water and at a temperature of 25°C. Based on the obtained data, the magnetic moments of lithium nuclei were calculated: μ(6Li) = 0.8220454(25)μN, μ(7Li) = 3.2564171(98)μN. The known data on the magnetic moment of the proton and data on the electronic shielding of these nuclei were used. A comparison of the experimental data for μ(6Li) and μ(7Li) and the corresponding theoretical calculation data was performed.