Physics:Isotopes of hafnium
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Standard atomic weight Ar, standard(Hf) |
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Natural hafnium (72Hf) consists of five observationally stable isotopes (176Hf, 177Hf, 178Hf, 179Hf, and 180Hf) and one very long-lived radioisotope, 174Hf, with a half-life of 7.0×1016 years.[2] In addition, there are 34 known synthetic radioisotopes, the most stable of which is 182Hf with a half-life of 8.9×106 years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.[3]
No other radioisotope has a half-life over 1.87 years. Most isotopes have half-lives under 1 minute. There are also at least 27 nuclear isomers, the most stable of which is 178m2Hf with a half-life of 31 years. All isotopes of hafnium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
List of isotopes
Nuclide [n 1] |
Z | N | Isotopic mass (u) [n 2][n 3] |
Half-life [n 4][n 5] |
Decay mode [n 6] |
Daughter isotope [n 7] |
Spin and parity [n 8][n 5] |
Physics:Natural abundance (mole fraction) | |
---|---|---|---|---|---|---|---|---|---|
Excitation energy[n 5] | Normal proportion | Range of variation | |||||||
153Hf | 72 | 81 | 152.97069(54)# | 400# ms [>200 ns] | 1/2+# | ||||
153mHf | 750(100)# keV | 500# ms | 11/2−# | ||||||
154Hf | 72 | 82 | 153.96486(54)# | 2(1) s | β+ | 154Lu | 0+ | ||
α (rare) | 150Yb | ||||||||
155Hf | 72 | 83 | 154.96339(43)# | 890(120) ms | β+ | 155Lu | 7/2−# | ||
α (rare) | 151Yb | ||||||||
156Hf | 72 | 84 | 155.95936(22) | 23(1) ms | α (97%) | 152Yb | 0+ | ||
β+ (3%) | 156Lu | ||||||||
156mHf | 1959.0(10) keV | 480(40) μs | 8+ | ||||||
157Hf | 72 | 85 | 156.95840(21)# | 115(1) ms | α (86%) | 153Yb | 7/2− | ||
β+ (14%) | 157Lu | ||||||||
158Hf | 72 | 86 | 157.954799(19) | 2.84(7) s | β+ (55%) | 158Lu | 0+ | ||
α (45%) | 154Yb | ||||||||
159Hf | 72 | 87 | 158.953995(18) | 5.20(10) s | β+ (59%) | 159Lu | 7/2−# | ||
α (41%) | 155Yb | ||||||||
160Hf | 72 | 88 | 159.950684(12) | 13.6(2) s | β+ (99.3%) | 160Lu | 0+ | ||
α (.7%) | 156Yb | ||||||||
161Hf | 72 | 89 | 160.950275(24) | 18.2(5) s | β+ (99.7%) | 161Lu | 3/2−# | ||
α (.3%) | 157Yb | ||||||||
162Hf | 72 | 90 | 161.94721(1) | 39.4(9) s | β+ (99.99%) | 162Lu | 0+ | ||
α (.008%) | 158Yb | ||||||||
163Hf | 72 | 91 | 162.94709(3) | 40.0(6) s | β+ | 163Lu | 3/2−# | ||
α (10−4%) | 159Yb | ||||||||
164Hf | 72 | 92 | 163.944367(22) | 111(8) s | β+ | 164Lu | 0+ | ||
165Hf | 72 | 93 | 164.94457(3) | 76(4) s | β+ | 165Lu | (5/2−) | ||
166Hf | 72 | 94 | 165.94218(3) | 6.77(30) min | β+ | 166Lu | 0+ | ||
167Hf | 72 | 95 | 166.94260(3) | 2.05(5) min | β+ | 167Lu | (5/2)− | ||
168Hf | 72 | 96 | 167.94057(3) | 25.95(20) min | β+ | 168Lu | 0+ | ||
169Hf | 72 | 97 | 168.94126(3) | 3.24(4) min | β+ | 169Lu | (5/2)− | ||
170Hf | 72 | 98 | 169.93961(3) | 16.01(13) h | EC | 170Lu | 0+ | ||
171Hf | 72 | 99 | 170.94049(3) | 12.1(4) h | β+ | 171Lu | 7/2(+) | ||
171mHf | 21.93(9) keV | 29.5(9) s | IT | 171Hf | 1/2(−) | ||||
172Hf | 72 | 100 | 171.939448(26) | 1.87(3) y | EC | 172Lu | 0+ | ||
172mHf | 2005.58(11) keV | 163(3) ns | (8−) | ||||||
173Hf | 72 | 101 | 172.94051(3) | 23.6(1) h | β+ | 173Lu | 1/2− | ||
174Hf[n 9] | 72 | 102 | 173.940046(3) | 7.0(12)×1016 y[2] | α[n 10] | 170Yb | 0+ | 0.0016(1) | 0.001619–0.001621 |
174m1Hf | 1549.3 keV | 138(4) ns | (6+) | ||||||
174m2Hf | 1797.5(20) keV | 2.39(4) μs | (8−) | ||||||
174m3Hf | 3311.7 keV | 3.7(2) μs | (14+) | ||||||
175Hf | 72 | 103 | 174.941509(3) | 70(2) d | β+ | 175Lu | 5/2− | ||
176Hf[n 11] | 72 | 104 | 175.9414086(24) | Observationally Stable[n 12] | 0+ | 0.0526(7) | 0.05206–0.05271 | ||
177Hf | 72 | 105 | 176.9432207(23) | Observationally Stable[n 13] | 7/2− | 0.1860(9) | 0.18593–0.18606 | ||
177m1Hf | 1315.4504(8) keV | 1.09(5) s | 23/2+ | ||||||
177m2Hf | 1342.38(20) keV | 55.9(12) μs | (19/2−) | ||||||
177m3Hf | 2740.02(15) keV | 51.4(5) min | 37/2− | ||||||
178Hf | 72 | 106 | 177.9436988(23) | Observationally Stable[n 14] | 0+ | 0.2728(7) | 0.27278–0.27297 | ||
178m1Hf | 1147.423(5) keV | 4.0(2) s | 8− | ||||||
178m2Hf | 2445.69(11) keV | 31(1) y | 16+ | ||||||
178m3Hf | 2573.5(5) keV | 68(2) μs | (14−) | ||||||
179Hf | 72 | 107 | 178.9458161(23) | Observationally Stable[n 15] | 9/2+ | 0.1362(2) | 0.13619–0.1363 | ||
179m1Hf | 375.0367(25) keV | 18.67(4) s | 1/2− | ||||||
179m2Hf | 1105.84(19) keV | 25.05(25) d | 25/2− | ||||||
180Hf | 72 | 108 | 179.9465500(23) | Observationally Stable[n 16] | 0+ | 0.3508(16) | 0.35076–0.351 | ||
180m1Hf | 1141.48(4) keV | 5.47(4) h | 8− | ||||||
180m2Hf | 1374.15(4) keV | 0.57(2) μs | (4−) | ||||||
180m3Hf | 2425.8(10) keV | 15(5) μs | (10+) | ||||||
180m4Hf | 2486.3(9) keV | 10(1) μs | 12+ | ||||||
180m5Hf | 2538.3(12) keV | >10 μs | (14+) | ||||||
180m6Hf | 3599.3(18) keV | 90(10) μs | (18−) | ||||||
181Hf | 72 | 109 | 180.9491012(23) | 42.39(6) d | β− | 181Ta | 1/2− | ||
181m1Hf | 595(3) keV | 80(5) μs | (9/2+) | ||||||
181m2Hf | 1040(10) keV | ~100 μs | (17/2+) | ||||||
181m3Hf | 1738(10) keV | 1.5(5) ms | (27/2−) | ||||||
182Hf | 72 | 110 | 181.950554(7) | 8.90(9)×106 y | β− | 182Ta | 0+ | ||
182mHf | 1172.88(18) keV | 61.5(15) min | β− (58%) | 182Ta | 8− | ||||
IT (42%) | 182Hf | ||||||||
183Hf | 72 | 111 | 182.95353(3) | 1.067(17) h | β− | 183Ta | (3/2−) | ||
184Hf | 72 | 112 | 183.95545(4) | 4.12(5) h | β− | 184Ta | 0+ | ||
184mHf | 1272.4(4) keV | 48(10) s | β− | 184Ta | 8− | ||||
185Hf | 72 | 113 | 184.95882(21)# | 3.5(6) min | β− | 185Ta | 3/2−# | ||
186Hf | 72 | 114 | 185.96089(32)# | 2.6(12) min | β− | 186Ta | 0+ | ||
187Hf | 72 | 115 | 186.96457(22)# | 14# s [>300 ns] | 9/2−# | ||||
187mHf | 500(300)# keV | 270(80) ns | IT | 187Hf | 3/2−# | ||||
188Hf | 72 | 116 | 187.96690(32)# | 20# s [>300 ns] | 0+ | ||||
189Hf | 72 | 117 | 188.97085(32)# | 400# ms [>300 ns] | 3/2−# | ||||
190Hf | 72 | 118 | 189.97338(43)# | 600# ms [>300 ns] | 0+ | ||||
191Hf[4] | 72 | 119 | |||||||
192Hf[4] | 72 | 120 | 0+ |
- ↑ mHf – Excited nuclear isomer.
- ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- ↑ Bold half-life – nearly stable, half-life longer than age of universe.
- ↑ 5.0 5.1 5.2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ↑
Modes of decay:
EC: Electron capture IT: Isomeric transition - ↑ Bold symbol as daughter – Daughter product is stable.
- ↑ ( ) spin value – Indicates spin with weak assignment arguments.
- ↑ primordial radionuclide
- ↑ Theorized to also undergo β+β+ decay to 174Yb
- ↑ Used in lutetium-hafnium dating
- ↑ Believed to undergo α decay to 172Yb
- ↑ Believed to undergo α decay to 173Yb
- ↑ Believed to undergo α decay to 174Yb
- ↑ Believed to undergo α decay to 175Yb
- ↑ Believed to undergo α decay to 176Yb
References
- ↑ Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ↑ 2.0 2.1 Cite error: Invalid
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tag; no text was provided for refs named174Hf2020
- ↑ "Tungsten Isotopes in Planets". Annual Review of Earth and Planetary Sciences 45 (1): 389–417. August 2017. doi:10.1146/annurev-earth-063016-020037. PMID 30842690. Bibcode: 2017AREPS..45..389K.
- ↑ 4.0 4.1 Haak, K.Expression error: Unrecognized word "et". (2023). "Production and discovery of neutron-rich isotopes by fragmentation of 198Pt". Physical Review C 108 (34608): 034608. doi:10.1103/PhysRevC.108.034608. Bibcode: 2023PhRvC.108c4608H.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A 729: 3–128, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- Isotopic compositions and standard atomic masses from:
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051.
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A 729: 3–128, doi:10.1016/j.nuclphysa.2003.11.001, Bibcode: 2003NuPhA.729....3A, https://hal.archives-ouvertes.fr/in2p3-00020241/document
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/.
- Lide, David R., ed (2004). "11. Table of the Isotopes". CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
Original source: https://en.wikipedia.org/wiki/Isotopes of hafnium.
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