Hyperfine Structure Investigation of¹⁵³Dy,¹⁵⁵Dy and¹⁵⁷Dy

The magnetic dipole and the electric quadrupole interaction constants a and b have been measured for the neutron-deficient dysprosium isotopes 153 Dy (6 h), 155 Dy (10 h) and 157 Dy (8.1 h) using the atomic-beam magnetic resonance method. The results are 157 Dy | a | = 121.605 (4) MHz | b | = 564.65 (7) MHz b/a < 0 155 Dy | a | = 136.5 (5) MHz | b | = 421 (5) MHz b/a <0 153 Dy | a | = 123.5 (8) MHz | b | = 65 (40) MHz b/a >0 For the evaluation of the corresponding nuclear moments of these isotopes a theoretical analysis of the hyperfine structure has been performed using an effective hyperfine structure Hamiltonian within the 4 f 10 configuration. The values of ⟨ r -3 ⟩ needed for the calculation have been obtained using relativistic self-consistent-field wavefunctions. The analysis yields the following nuclear moments: 157 Dy: μ I = -0.30 (3) n.m. Q = +1.22 (13) barn 155 Dy: μ I = -0.34 (3) n.m. Q = +0.91 (10) barn 153 Dy: μ I = -0.71 (9) n.m. Q = -0.14 (8) barn The quadrupole moments are corrected for the Sternheimer effect. A comparison with recent moment calculations using the unified nuclear model is made.