Nuclear Spins of Neutron-deficient Promethium, Samarium, Europium and Gadolinium Isotopes

Spin-measurements have been performed on some neutron-deficient promethium, samarium, europium and gadolinium isotopes using conventional atomic-beam magnetic resonance techniques. The results are: 141 Pm (20.9 min) I =5/2, 140 Sm (14.8 min) I =0, 141 Sm (11.3 min) I =1/2, 141m Sm (22.9 min) I =11/2, 142 Sm (72.5 min) I =0, 143 Sm (8.8 min) I =3/2, 145 Eu (5.93 d) I =5/2, 146 Eu (4.65 d) I =4, 147 Eu (22 d) I =5/2, 148 Eu (54 d) I =5, 149 Eu (93.1 d) I =5/2, 150 Eu (12.6 h) I =0, 145 Gd (22.9 min) I =1/2, 147 Gd (38.5 h) I =7/2, 149 Gd (9.4 d) I =7/2, 151 Gd (120 d) I =7/2. The investigated nuclei appear close to the shell closure at neutron number N =82. A systematic review of the low-lying states of odd-even and doubly-odd nuclei in this region is presented.