NQR spectroscopy is possible for isotopes with a nuclear spin I > 1/2 and a high isotopic abundance. An EFG unequal to zero is just possible if the isotope is at a site in a solid that has symmetry lower than tetragonal [1]. Table 1 shows a selection of quadrupolar nuclei.
Isotope | natural abundance [%] | Spin quantum number I | γ [MHz / T] | electric quadrupole moment eQ [e * 10-24 cm2] |
---|---|---|---|---|
55Mn | 100 | 5/2 | 10,501 | 0,4 |
59Co | 100 | 7/2 | 10,054 | 0,404 |
75As | 100 | 3/2 | 7,2919 | 0,29 |
79Br | 50,69 | 3/2 | 10,667 | 0,293 |
81Br | 49,31 | 3/2 | 11,498 | 0,27 |
85Rb | 72,165 | 5/2 | 4,1108 | 0,274 |
93Nb | 100 | 9/2 | 10,407 | -0,36 |
115In | 95,7 | 9/2 | 9,3301 | 0,861 |
121Sb | 57,3 | 5/2 | 10,189 | -0,2 |
123Sb | 42,7 | 7/2 | 5,5176 | -0,26 |
127I | 100 | 5/2 | 8,5183 | -0,789 |
139La | 99,91 | 7/2 | 6,0144 | 0,22 |
181Ta | 99,988 | 7/2 | 5,096 | 3,9 |
197Au | 100 | 3/2 | 0,7292 | 0,594 |
209Bi
| 100 | 9/2 | 6,84178 | -0,46 |