Measurement of the anomalous nuclear magnetic moment of trivalent europium

An order-of-magnitude reduction of the nuclear magnetic moment of trivalent europium due to hyperfine-induced magnetic shielding was predicted by Elliott in 1957. With use of optical hole burning and optically detected nuclear quadrupole resonance in YAlO3: Eu3+, this shielding has been measured for the first time. We find that the ground-state moment is reduced to 21% of its intrinsic value, while the moment in the excited D05 state is unaffected. © 1981 The American Physical Society.