Nuclear quadrupole resonance of 139La around Pr3+ doped in LaF3. Raman heterodyne detection using optical transition of Pr3+ ions

The quadrupole transitions of 139La nuclei around Pr3+ doped in LaF3 have been detected as an optical-rf induced coherent Raman beat on the Pr3+ 3H43P0 transition (25 cm−1) at 1.5 K. Because the effective 141Pr nuclear magnetic moment is smaller in the excited 3P0 state than in the ground state, the Pr-La interaction decreases upon Pr3+ optical excitation, which makes the La quadrupole transitions couple with the Pr optical transition. Four magnetically inequivalent La nuclei were observed, revealing different local environments of La atoms around impurity Pr3+ ions.