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All atomic nuclei of the chemical element hafnium are summarized under hafnium isotopes; these all consist of an atomic nucleus with 72 protons and, in the uncharged state, 72 electrons. The difference between each hafnium isotope is based on the number of neutrons in the nucleus.
The natural terrestrial hafnium deposits consist of a mixture of 6 different isotopes: the stable hafnium nuclides Hf-176, 177, 178, 179 and 180 as well as the slightly radioactive, very long-lived radioisotope Hf-174. Overall, the isotope distribution for hafnium is as follows:
Atomic Mass ma | Quantity | Half-life | Spin | |
Hafnium Isotopic mixture | 178,486 u | 100 % | ||
Isotope 174Hf | 173,94005(2) u | 0,16(12) % | 2.0(4) × 1015 a | 0+ |
Isotope 176Hf | 175,94141(2) u | 5,26(70) % | stable | 0+ |
Isotope 177Hf | 176,94323(2) u | 18,60(16) % | stable | 7/2- |
Isotope 178Hf | 177,94371(2) u | 27,28(28) % | stable | 0+ |
Isotope 179Hf | 178,94582(2) u | 13,62(11) % | stable | 9/2+ |
Isotope 180Hf | 179,94656(2) u | 35,08(33) % | stable | 0+ |
Hafnium-182 is the most stable artificial hafnium isotope with a half-life of 9,000,000 years. There are no technical applications for individual hafnium isotopes.
Isotope Nuclide | E | N | Atomic Mass [Nuclear Mass] {Mass Excess} | Spin I (h/2π) | Parent |
---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 |
Hafnium-153 | 15372Hf | 81 | 152.97069(32) u [152.931196 u] {-27.30209 MeV} | ||
Hafnium-154 | 15472Hf | 82 | 153.96493(32) u [153.925436 u] {-32.66749 MeV} | 0+ | 158W |
Hafnium-155 | 15572Hf | 83 | 154.96332(32) u [154.923826 u] {-34.1672 MeV} | 159W 156Ta | |
Hafnium-156 | 15672Hf | 84 | 155.95940(16) u [155.919906 u] {-37.81866 MeV} | 0+ | 160W 156Ta |
Hafnium-156m | 156m72Hf | 84 | 155.95940(16) u [155.919906 u] {-37.81866 MeV} | 8+ | |
Hafnium-157 | 15772Hf | 85 | 156.95824(21) u [156.918746 u] {-38.89919 MeV} | (7/2-) | 161W |
Hafnium-158 | 15872Hf | 86 | 157.954801(19) u [157.915307 u] {-42.1026 MeV} | 0+ | 162W |
Hafnium-159 | 15972Hf | 87 | 158.953996(18) u [158.914502 u] {-42.85245 MeV} | 7/2- | 163W |
Hafnium-160 | 16072Hf | 88 | 159.950683(10) u [159.911189 u] {-45.93849 MeV} | 0+ | 164W |
Hafnium-161 | 16172Hf | 89 | 160.950279(24) u [160.910785 u] {-46.31481 MeV} | (7/2-) | 165W |
Hafnium-161m | 161m72Hf | 89 | 160.950279(24) u [160.910785 u] {-46.31481 MeV} | (13/2+) | |
Hafnium-162 | 16272Hf | 90 | 161.947215(10) u [161.907721 u] {-49.16891 MeV} | 0+ | 166W 162Ta |
Hafnium-163 | 16372Hf | 91 | 162.947113(27) u [162.907619 u] {-49.26392 MeV} | (5/2-) | 167W 163Ta |
Hafnium-164 | 16472Hf | 92 | 163.944371(17) u [163.904877 u] {-51.81808 MeV} | 0+ | 168W 164Ta |
Hafnium-165 | 16572Hf | 93 | 164.94457(3) u [164.905076 u] {-51.63271 MeV} | (5/2-) | 165Ta |
Hafnium-166 | 16672Hf | 94 | 165.94218(3) u [165.902686 u] {-53.85898 MeV} | 0+ | 166Ta |
Hafnium-167 | 16772Hf | 95 | 166.94260(3) u [166.903106 u] {-53.46776 MeV} | (5/2)- | 167Ta |
Hafnium-168 | 16872Hf | 96 | 167.94057(3) u [167.901076 u] {-55.35869 MeV} | 0+ | 168Ta |
Hafnium-169 | 16972Hf | 97 | 168.94126(3) u [168.901766 u] {-54.71596 MeV} | 5/2- | 169Ta |
Hafnium-170 | 17072Hf | 98 | 169.93961(3) u [169.900116 u] {-56.25292 MeV} | 0+ | 170Ta |
Hafnium-171 | 17172Hf | 99 | 170.94049(3) u [170.900996 u] {-55.43321 MeV} | 7/2(+) | 171Ta |
Hafnium-171m | 171m72Hf | 99 | 170.94049(3) u [170.900996 u] {-55.43321 MeV} | 1/2(-) | |
Hafnium-172 | 17272Hf | 100 | 171.939450(26) u [171.899956 u] {-56.40196 MeV} | 0+ | 172Ta |
Hafnium-172m | 172m72Hf | 100 | 171.939450(26) u [171.899956 u] {-56.40196 MeV} | (8-) | |
Hafnium-173 | 17372Hf | 101 | 172.94051(3) u [172.901016 u] {-55.41458 MeV} | 1/2- | 173Ta |
Hafnium-174 | 17472Hf | 102 | 173.94005(2) u [173.900556 u] {-55.84307 MeV} | 0+ | 174Ta |
Hafnium-175 | 17572Hf | 103 | 174.9415115(24) u [174.9020175 u] {-54.48169 MeV} | 5/2(-) | 175Ta |
Hafnium-176 | 17672Hf | 104 | 175.94141(2) u [175.901916 u] {-54.57623 MeV} | 0+ | 176Ta 176Lu |
Hafnium-177 | 17772Hf | 105 | 176.94323(2) u [176.903736 u] {-52.88091 MeV} | 7/2- | 177Ta 177Lu |
Hafnium-177m1 | 177m172Hf | 105 | 176.94323(2) u [176.903736 u] {-52.88091 MeV} | 23/2+ | |
Hafnium-177m2 | 177m272Hf | 105 | 176.94323(2) u [176.903736 u] {-52.88091 MeV} | (19/2-) | |
Hafnium-177m3 | 177m372Hf | 105 | 176.94323(2) u [176.903736 u] {-52.88091 MeV} | 37/2- | |
Hafnium-178 | 17872Hf | 106 | 177.94371(2) u [177.904216 u] {-52.4338 MeV} | 0+ | 178Ta 178Lu |
Hafnium-178m1 | 178m172Hf | 106 | 177.94371(2) u [177.904216 u] {-52.4338 MeV} | 8- | |
Hafnium-178m2 | 178m272Hf | 106 | 177.94371(2) u [177.904216 u] {-52.4338 MeV} | 16+ | |
Hafnium-179 | 17972Hf | 107 | 178.94582(2) u [178.906326 u] {-50.46834 MeV} | 9/2+ | 179Ta 179Lu |
Hafnium-179m1 | 179m172Hf | 107 | 178.94582(2) u [178.906326 u] {-50.46834 MeV} | 1/2- | |
Hafnium-179m2 | 179m272Hf | 107 | 178.94582(2) u [178.906326 u] {-50.46834 MeV} | 25/2- | |
Hafnium-180 | 18072Hf | 108 | 179.94656(2) u [179.907066 u] {-49.77904 MeV} | 0+ | 180Ta 180Lu |
Hafnium-180m | 180m72Hf | 108 | 179.94656(2) u [179.907066 u] {-49.77904 MeV} | 8- | |
Hafnium-181 | 18172Hf | 109 | 180.9491110(15) u [180.909617 u] {-47.4028 MeV} | 1/2- | 181Lu |
Hafnium-182 | 18272Hf | 110 | 181.950564(7) u [181.91107 u] {-46.04934 MeV} | 0+ | 182Lu |
Hafnium-182m | 182m72Hf | 110 | 181.950564(7) u [181.91107 u] {-46.04934 MeV} | (8-) | |
Hafnium-183 | 18372Hf | 111 | 182.95353(3) u [182.914036 u] {-43.28653 MeV} | (3/2-) | 183Lu |
Hafnium-184 | 18472Hf | 112 | 183.95545(4) u [183.915956 u] {-41.49806 MeV} | 0+ | 184Lu |
Hafnium-184m | 184m72Hf | 112 | 183.95545(4) u [183.915956 u] {-41.49806 MeV} | (8-) | |
Hafnium-185 | 18572Hf | 113 | 184.95886(7) u [184.919366 u] {-38.32166 MeV} | ||
Hafnium-186 | 18672Hf | 114 | 185.96090(5) u [185.921406 u] {-36.42142 MeV} | 0+ | |
Hafnium-187 | 18772Hf | 115 | 186.96477(32) u [186.925276 u] {-32.81653 MeV} | ||
Hafnium-188 | 18872Hf | 116 | 187.96685(32) u [187.927356 u] {-30.87903 MeV} | 0+ | |
Hafnium-189 | 18972Hf | 117 | 188.97084(32) u [188.931346 u] {-27.16237 MeV} | ||
Hafnium-190 | 19072Hf | 118 | 189.97313(43) u [189.933636 u] {-25.02924 MeV} | 0+ |
Isotope | Radioactive Decay | Extern | |||
---|---|---|---|---|---|
Half-life | Decay Mode | Probability | Energy | ||
7 | 8 | 9 | 10 | 11 | 12 |
Hf-153 | 60 ns | AL | |||
Hf-154 | 2(1) s | EC/β+ → 154Lu α → 150Yb | ca. 100 % ca. 0 % | 7.04(36) MeV 3.54(42) MeV | AL |
Hf-155 | 0.89(12) s | EC/β+ → 155Lu | 100 % | 8.38(30) MeV | AL |
Hf-156 | 23(1) ms | α → 152Yb | 100 % | 6.029(4) MeV | AL |
Hf-156m | 0.52(1) ms | α → 152Yb | 100 % | AL | |
Hf-157 | 115(1) ms | EC/β+ → 157Lu α → 153Yb | 14(9) % 86(9) % | 7.54(20) MeV 5.880(3) MeV | AL |
Hf-158 | 2.85(7) s | EC/β+ → 158Lu α → 154Yb | 55.7(19) % 44.3(19) % | 5.110(23) MeV 5.4048(27) MeV | AL |
Hf-159 | 5.6(4) s | EC/β+ → 159Lu α → 155Yb | 65(7) % 35(7) % | 6.86(4) MeV 5.2251(27) MeV | AL |
Hf-160 | 13.6(2) s | EC/β+ → 160Lu α → 156Yb | 99.3(2) % 0.7(2) % | 4.33(6) MeV 4.9019(26) MeV | AL |
Hf-161 | 18.4(4)s | EC/β+ → 161Lu α → 157Yb | > 99.87 % < 0.13 % | 6.25(4) MeV 4.682(24) MeV | AL |
Hf-161m | 4.8(2) μs | Iso → 161Hf | 100 % | ||
Hf-162 | 39.4(9) s | EC/β+ → 162Lu α → 158Yb | 99.992(1) % 0.008(1) % | 3.66(8) MeV 4.416(5) MeV | AL |
Hf-163 | 40.0(6) s | EC/β+ → 163Lu α → 159Yb | > 99.9998 % < 0.0001 % | 5.53(4) MeV 4.15(3) MeV | AL |
Hf-164 | 111(8) s | EC/β+ → 164Lu | 100 % | 2.82(3) MeV | AL |
Hf-165 | 76(4) s | EC/β+ → 165Lu | 100 % | 4.81(4) MeV | AL |
Hf-166 | 6.77(30) min | EC/β+ → 166Lu | 100 % | 2.16(4) MeV | AL |
Hf-167 | 2.05(5) min | EC/β+ → 167Lu | 100 % | 4.03(4) MeV | AL |
Hf-168 | 25.95(20) min | EC/β+ → 168Lu | 100 % | 1.71(5) MeV | AL |
Hf-169 | 3.24(4) min | EC/β+ → 169Lu | 100 % | 3.368(28) MeV | AL |
Hf-170 | 16.01(13) h | EC → 170Lu | 100 % | 1.05(3) MeV | AL |
Hf-171 | 12.1(4) h | EC/β+ → 171Lu | 100 % | 2.397(29) MeV | AL |
Hf-171m | 29.5(9) s | EC/β+ → 171Lu Iso → 171Hf | ? ≤ 100 % | AL | |
Hf-172 | 1.87(3) a | EC → 172Lu | 100 % | 0.334(25) MeV | AL |
Hf-172m | 163(3) ns | Iso → 172Hf | |||
Hf-173 | 23.6(1) h | EC/β+ → 173Lu | 100 % | 1.469(28) MeV | AL |
Hf-174 | 2.0(4) × 1015 a | α → 170Yb | 100 % | 2.4945(23) MeV | AL |
Hf-175 | 70(2) d | EC → 175Lu | 100 % | 0.6839(26) MeV | AL |
Hf-176 | stable | AL | |||
Hf-177 | stable | AL | |||
Hf-177m1 | 1.09(5) s | Iso → 177Hf | 100 % | ||
Hf-177m2 | 55.9(12) μs | ||||
Hf-177m3 | 51.4(5) min | Iso → 177Hf | 100 % | ||
Hf-178 | stable | AL | |||
Hf-178m1 | 4.0(2) s | Iso → 178Hf | 100 % | ||
Hf-178m2 | 31(1) a | Iso → 178Hf | 100 % | ||
Hf-179 | stable | AL | |||
Hf-179m1 | 18.67(4) s | Iso → 179Hf | 100 % | ||
Hf-179m2 | 25.05(25) d | Iso → 179Hf | 100 % | ||
Hf-180 | stable | AL | |||
Hf-180m | 5.53(2) h | Iso → 180Hf β- → 180Ta | 99.7(1) % 0.3(1) % | ||
Hf-181 | 42.39 d | β- → 181Ta | 100 % | 1.0355(18) MeV | AL |
Hf-182 | 8.90(9) × 106 a | β- → 182Ta | 100 % | 0.380(6) MeV | AL |
Hf-182m | 61.5(15) min | β- → 182Ta Iso → 182Hf | 54(2) % 46(2) % | ||
Hf-183 | 1.018(2) h | β- → 183Ta | 100 % | 2.01(3) MeV | AL |
Hf-184 | 4.12(5) h | β- → 184Ta | 100 % | 1.34(3) MeV | AL |
Hf-184m | 48(10) s | Iso → 184Hf | 100 % | ||
Hf-185 | 3.5(6) min | β- → 185Ta | 100 % | 3.07(7) MeV | AL |
Hf-186 | 2.6(12) min | β- → 186Ta | 100 % | 2.18(8) MeV | AL |
Hf-187 | β- → 187Ta | 100 % | 4.08(30) MeV | AL | |
Hf-188 | β- → 188Ta | 100 % | 2.73(30) MeV | AL | |
Hf-189 | > 300 ns | β- → 189Ta | 100 % | 4.67(36) MeV | AL |
Hf-190 | 160 ns | β- → 190Ta | ? | 3.48(45) MeV |
Notes (related to the columns):
1 - name of the nuclide, isotope.
2 - E: isotope symbol with mass number (superscript; number of nucleons) and atomic number (subscript; number of protons).
3 - N: number of neutrons.
4 - relative atomic mass of the Hafnium isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
5 - nuclear spin I, unit: h/2π.
6 - source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
7 - isotope notation in short form.
8 - decay: half-live of the Hafnium isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
9 - decay mode: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
10 - decay probability in percent (%).
11 - decay energy; Particle energy related to decay type.
12 - other information and notes: AL = Adopted Levels (link to external data [1]).
Miscellaneous:
()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
- unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.
Nuclide quantity 1) spin | Nuclear magnetic moment μ/μN | Gyromagnetic ratio {Quadrupole moment} | Resonant frequency v0 bei 1 T | Relative sensitivity H0 = const. v0 = const. 3) |
---|---|---|---|---|
177Hf 18,60(16) % 7/2- | + 0,7935 | 1,086 {+ 336,5(29)} | 1,7282 | 0,00140 0,8524 |
179Hf 13,62(11) % 9/2+ | - 0,60409(13) | 0,6821 {+ 379,3(33)} | 1,0856 | 0,00055 0,8414 |
1) Quantity Percentage of natural occurrence.
2) Gyromagnetic ratio: 107 rad T-1 s-1
Quadrupole moment: Q fm-2
3) Related to 1H = 1,000.
According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Hafnium radionuclides:
Nuclide | Limit Value | HASS limit | SC | Daughter Nuclides | Half-life | |
---|---|---|---|---|---|---|
Hf-170+ | 106 Bq | 100 Bq/g | 16.0 h | |||
Hf-172+ | 106 Bq | 1 Bq/g | 0,04 TBq | 1.9 a | ||
Hf-173 | 106 Bq | 100 Bq/g | 23.9 h | |||
Hf-175 | 106 Bq | 1 Bq/g | 0,2 TBq | 70.0 d | ||
Hf-177m+ | 105 Bq | 10 Bq/g | 51.4 min | |||
Hf-178m+ | 106 Bq | 0,1 Bq/g | 31.0 a | |||
Hf-179m | 106 Bq | 10 Bq/g | 25.0 d | |||
Hf-180m | 106 Bq | 10 Bq/g | 5.5 h | |||
Hf-181 | 106 Bq | 1 Bq/g | 0,1 TBq | 1 Bq cm-2 | 42.4 d | |
Hf-182+ | 106 Bq | 0,1 Bq/g | 0,05 TBq | 9000000 a | ||
Hf-182m+ | 106 Bq | 10 Bq/g | 61.5 min | |||
Hf-183 | 106 Bq | 10 Bq/g | 64.0 min | |||
Hf-184 | 106 Bq | 100 Bq/g | 4.1 h |
(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)
Properties of the Hafnium nucleides
[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.
[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.
[3] - Live Chart of Nuclides. Nuclear structure and decay data.
Hafnium: NMR properties - 177Hf-NMR, 179Hf-NMR
[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.
[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.
[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.
[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).
More sources:
[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.
[9] - J. L. Gross, M. Thoennessen:
Discovery of gallium, germanium, lutetium, and hafnium isotopes.
In: Atomic Data and Nuclear Data Tables, (2012), DOI 10.1016/j.adt.2011.09.004.
Last update: 2022-12-12
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