Isotopes of hafnium

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 years. The next most stable radioisotope is ¹⁸²Hf with a half-life of 8.90 million years, an extinct radionuclide used in hafnium–tungsten dating to study the chronology of planetary differentiation.

Other isotopes have been synthesized running from ¹⁵³Hf to ¹⁹²Hf, but none of the 33 others has a half-life over 1.87 years, and most have half-lives under five minutes. There are also at least 41 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

|-id=Hafnium-153 | ¹⁵³Hf | style="text-align:right" | 72 | style="text-align:right" | 81 | 152.97069(32)# | 400#&nbsp;ms<br/>[>200&nbsp;ns] | | | 1/2+# | | |-id=Hafnium-154 | rowspan=2|¹⁵⁴Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 82 | rowspan=2|153.96486(32)# | rowspan=2|2(1)&nbsp;s | β⁺ | ¹⁵⁴Lu | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (rare) | ¹⁵⁰Yb |-id=Hafnium-154m | style="text-indent:1em" | ^154mHf | colspan="3" style="text-indent:2em" | 2721(50)#&nbsp;keV | 9(4)&nbsp;μs | IT | ¹⁵⁴Hf | (10+) | | |-id=Hafnium-155 | ¹⁵⁵Hf | style="text-align:right" | 72 | style="text-align:right" | 83 | 154.96317(32)# | 843(30)&nbsp;ms | β⁺ | ¹⁵⁵Lu | 7/2−# | | |-id=Hafnium-156 | ¹⁵⁶Hf | style="text-align:right" | 72 | style="text-align:right" | 84 | 155.95940(16) | 23(1)&nbsp;ms | α | ¹⁵²Yb | 0+ | | |-id=Hafnium-156m | style="text-indent:1em" | ^156mHf | colspan="3" style="text-indent:2em" | 1958.8(10)&nbsp;keV | 480(40)&nbsp;μs | α | ¹⁵²Yb | (8+) | | |-id=Hafnium-157 | rowspan=2|¹⁵⁷Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 85 | rowspan=2|156.95829(22)# | rowspan=2|115(1)&nbsp;ms | α (94%) | ¹⁵³Yb | rowspan=2|7/2− | rowspan=2| | rowspan=2| |- | β⁺ (6%) | ¹⁵⁷Lu |-id=Hafnium-158 | rowspan=2|¹⁵⁸Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 86 | rowspan=2|157.954801(19) | rowspan=2|2.85(7)&nbsp;s | β⁺ (55.7%) | ¹⁵⁸Lu | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (44.3%) | ¹⁵⁴Yb |-id=Hafnium-159 | rowspan=2|¹⁵⁹Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 87 | rowspan=2|158.953996(18) | rowspan=2|5.20(10)&nbsp;s | β⁺ (65%) | ¹⁵⁹Lu | rowspan=2|7/2− | rowspan=2| | rowspan=2| |- | α (35%) | ¹⁵⁵Yb |-id=Hafnium-160 | rowspan=2|¹⁶⁰Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 88 | rowspan=2|159.950683(10) | rowspan=2|13.6(2)&nbsp;s | β⁺ (99.3%) | ¹⁶⁰Lu | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (0.7%) | ¹⁵⁶Yb |-id=Hafnium-161 | rowspan=2|¹⁶¹Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 89 | rowspan=2|160.950278(25) | rowspan=2|18.4(4)&nbsp;s | β⁺ (99.71%) | ¹⁶¹Lu | rowspan=2|(7/2−) | rowspan=2| | rowspan=2| |- | α (0.29%) | ¹⁵⁷Yb |-id=Hafnium-161m | style="text-indent:1em" | ^161mHf | colspan="3" style="text-indent:2em" | 329.0(5)&nbsp;keV | 4.8(2)&nbsp;μs | IT | ¹⁶¹Hf | (13/2+) | | |-id=Hafnium-162 | rowspan=2|¹⁶²Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 90 | rowspan=2|161.9472155(96) | rowspan=2|39.4(9)&nbsp;s | β⁺ (99.99%) | ¹⁶²Lu | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (0.008%) | ¹⁵⁸Yb |-id=Hafnium-163 | ¹⁶³Hf | style="text-align:right" | 72 | style="text-align:right" | 91 | 162.947107(28) | 40.0(6)&nbsp;s | β⁺ | ¹⁶³Lu | (5/2−) | | |-id=Hafnium-164 | ¹⁶⁴Hf | style="text-align:right" | 72 | style="text-align:right" | 92 | 163.944371(17) | 111(8)&nbsp;s | β⁺ | ¹⁶⁴Lu | 0+ | | |-id=Hafnium-165 | ¹⁶⁵Hf | style="text-align:right" | 72 | style="text-align:right" | 93 | 164.944567(30) | 76(4)&nbsp;s | β⁺ | ¹⁶⁵Lu | (5/2−) | | |-id=Hafnium-166 | ¹⁶⁶Hf | style="text-align:right" | 72 | style="text-align:right" | 94 | 165.942180(30) | 6.77(30)&nbsp;min | β⁺ | ¹⁶⁶Lu | 0+ | | |-id=Hafnium-167 | ¹⁶⁷Hf | style="text-align:right" | 72 | style="text-align:right" | 95 | 166.942600(30) | 2.05(5)&nbsp;min | β⁺ | ¹⁶⁷Lu | (5/2)− | | |-id=Hafnium-168 | rowspan=2|¹⁶⁸Hf | rowspan=2 style="text-align:right" | 72 | rowspan=2 style="text-align:right" | 96 | rowspan=2|167.940568(30) | rowspan=2|25.95(20)&nbsp;min | EC (98%) | ¹⁶⁸Lu | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺ (2%) | ¹⁶⁸Lu |-id=Hafnium-169 | ¹⁶⁹Hf | style="text-align:right" | 72 | style="text-align:right" | 97 | 168.941259(30) | 3.24(4)&nbsp;min | β⁺ | ¹⁶⁹Lu | (5/2−) | | |-id=Hafnium-170 | ¹⁷⁰Hf | style="text-align:right" | 72 | style="text-align:right" | 98 | 169.939609(30) | 16.01(13)&nbsp;h | EC | ¹⁷⁰Lu | 0+ | | |-id=Hafnium-171 | ¹⁷¹Hf | style="text-align:right" | 72 | style="text-align:right" | 99 | 170.940492(31) | 12.1(4)&nbsp;h | β⁺ | ¹⁷¹Lu | 7/2+ | | |-id=Hafnium-171m | style="text-indent:1em" | ^171mHf | colspan="3" style="text-indent:2em" | 21.93(9)&nbsp;keV | 29.5(9)&nbsp;s | IT | ¹⁷¹Hf | 1/2− | | |-id=Hafnium-172 | ¹⁷²Hf | style="text-align:right" | 72 | style="text-align:right" | 100 | 171.939450(26) | 1.87(3)&nbsp;y | EC | ¹⁷²Lu | 0+ | | |-id=Hafnium-172m | style="text-indent:1em" | ^172mHf | colspan="3" style="text-indent:2em" | 2005.84(11)&nbsp;keV | 163(3)&nbsp;ns | IT | ¹⁷²Hf | (8−) | | |-id=Hafnium-173 | ¹⁷³Hf | style="text-align:right" | 72 | style="text-align:right" | 101 | 172.940513(30) | 23.6(1)&nbsp;h | β⁺ | ¹⁷³Lu | 1/2− | | |-id=Hafnium-173m1 | style="text-indent:1em" | ^173m1Hf | colspan="3" style="text-indent:2em" | 107.16(5)&nbsp;keV | 180(8)&nbsp;ns | IT | ¹⁷³Hf | 5/2− | | |-id=Hafnium-173m2 | style="text-indent:1em" | ^173m2Hf | colspan="3" style="text-indent:2em" | 197.47(10)&nbsp;keV | 160(40)&nbsp;ns | IT | ¹⁷³Hf | 7/2+ | | |-id=Hafnium-174 | ¹⁷⁴Hf | style="text-align:right" | 72 | style="text-align:right" | 102 | 173.9400484(24) | | α | ¹⁷⁰Yb | 0+ | 0.0016(12) | |-id=Hafnium-174m1 | style="text-indent:1em" | ^174m1Hf | colspan="3" style="text-indent:2em" | 1549.26(4)&nbsp;keV | 138(4)&nbsp;ns | IT | ¹⁷⁴Hf | 6+ | | |-id=Hafnium-174m2 | style="text-indent:1em" | ^174m2Hf | colspan="3" style="text-indent:2em" | 1797.59(7)&nbsp;keV | 2.39(4)&nbsp;μs | IT | ¹⁷⁴Hf | 8− | | |-id=Hafnium-174m3 | style="text-indent:1em" | ^174m3Hf | colspan="3" style="text-indent:2em" | 3312.07(6)&nbsp;keV | 3.7(2)&nbsp;μs | IT | ¹⁷⁴Hf | 14+ | | |-id=Hafnium-175 | ¹⁷⁵Hf | style="text-align:right" | 72 | style="text-align:right" | 103 | 174.9415114(25) | 69.90(7)&nbsp;d | EC | ¹⁷⁵Lu | 5/2− | | |-id=Hafnium-175m1 | style="text-indent:1em" | ^175m1Hf | colspan="3" style="text-indent:2em" | 125.89(12)&nbsp;keV | 53.7(15)&nbsp;μs | IT | ¹⁷⁵Hf | 1/2− | | |-id=Hafnium-175m2 | style="text-indent:1em" | ^175m2Hf | colspan="3" style="text-indent:2em" | 1433.41(12)&nbsp;keV | 1.10(8)&nbsp;μs | IT | ¹⁷⁵Hf | 19/2+ | | |-id=Hafnium-175m3 | style="text-indent:1em" | ^175m3Hf | colspan="3" style="text-indent:2em" | 3015.6(4)&nbsp;keV | 1.21(15)&nbsp;μs | IT | ¹⁷⁵Hf | 35/2− | | |-id=Hafnium-175m4 | style="text-indent:1em" | ^175m4Hf | colspan="3" style="text-indent:2em" | 4636.2(12)&nbsp;keV | 1.9(1)&nbsp;μs | IT | ¹⁷⁵Hf | 45/2+ | | |-id=Hafnium-176 | ¹⁷⁶Hf | style="text-align:right" | 72 | style="text-align:right" | 104 | 175.9414098(16) | colspan=3 align=center|Observationally Stable | 0+ | 0.0526(70) | |-id=Hafnium-176m1 | style="text-indent:1em" | ^176m1Hf | colspan="3" style="text-indent:2em" | 1333.07(7)&nbsp;keV | 9.6(3)&nbsp;μs | IT | ¹⁷⁶Hf | 6+ | | |-id=Hafnium-176m2 | style="text-indent:1em" | ^176m2Hf | colspan="3" style="text-indent:2em" | 1559.31(9)&nbsp;keV | 9.9(2)&nbsp;μs | IT | ¹⁷⁶Hf | 8− | | |-id=Hafnium-176m3 | style="text-indent:1em" | ^176m3Hf | colspan="3" style="text-indent:2em" | 2865.8(7)&nbsp;keV | 401(6)&nbsp;μs | IT | ¹⁷⁶Hf | 14− | | |-id=Hafnium-176m4 | style="text-indent:1em" | ^176m4Hf | colspan="3" style="text-indent:2em" | 4863.6(9)&nbsp;keV | 43(4)&nbsp;μs | IT | ¹⁷⁶Hf | 22− | | |-id=Hafnium-177 | ¹⁷⁷Hf | style="text-align:right" | 72 | style="text-align:right" | 105 | 176.9432302(15) | colspan=3 align=center|Observationally Stable | 7/2− | 0.1860(16) | |-id=Hafnium-177m1 | style="text-indent:1em" | ^177m1Hf | colspan="3" style="text-indent:2em" | 1315.4502(8)&nbsp;keV | 1.09(5)&nbsp;s | IT | ¹⁷⁷Hf | 23/2+ | | |-id=Hafnium-177m2 | style="text-indent:1em" | ^177m2Hf | colspan="3" style="text-indent:2em" | 1342.4(10)&nbsp;keV | 55.9(12)&nbsp;μs | IT | ¹⁷⁷Hf | (19/2−) | | |-id=Hafnium-177m3 | style="text-indent:1em" | ^177m3Hf | colspan="3" style="text-indent:2em" | 2740.02(15)&nbsp;keV | 51.4(5)&nbsp;min | IT | ¹⁷⁷Hf | 37/2− | | |-id=Hafnium-178 | ¹⁷⁸Hf | style="text-align:right" | 72 | style="text-align:right" | 106 | 177.9437083(15) | colspan=3 align=center|Observationally Stable | 0+ | 0.2728(28) | |-id=Hafnium-178m1 | style="text-indent:1em" | ^178m1Hf | colspan="3" style="text-indent:2em" | 1147.416(6)&nbsp;keV | 4.0(2)&nbsp;s | IT | ¹⁷⁸Hf | 8− | | |-id=Hafnium-178m2 | style="text-indent:1em" | ^178m2Hf | colspan="3" style="text-indent:2em" | 2446.09(8)&nbsp;keV | 31(1)&nbsp;y | IT | ¹⁷⁸Hf | 16+ | | |-id=Hafnium-178m3 | style="text-indent:1em" | ^178m3Hf | colspan="3" style="text-indent:2em" | 2572.4(3)&nbsp;keV | 68(2)&nbsp;μs | IT | ¹⁷⁸Hf | 14− | | |-id=Hafnium-179 | ¹⁷⁹Hf | style="text-align:right" | 72 | style="text-align:right" | 107 | 178.9458257(15) | colspan=3 align=center|Observationally Stable | 9/2+ | 0.1362(11) | |-id=Hafnium-179m1 | style="text-indent:1em" | ^179m1Hf | colspan="3" style="text-indent:2em" | 375.0352(25)&nbsp;keV | 18.67(4)&nbsp;s | IT | ¹⁷⁹Hf | 1/2− | | |-id=Hafnium-179m2 | style="text-indent:1em" | ^179m2Hf | colspan="3" style="text-indent:2em" | 1106.412(33)&nbsp;keV | 25.00(17)&nbsp;d | IT | ¹⁷⁹Hf | 25/2− | | |-id=Hafnium-179m3 | style="text-indent:1em" | ^179m3Hf | colspan="3" style="text-indent:2em" | 3775.2(21)&nbsp;keV | 15(5)&nbsp;μs | IT | ¹⁷⁹Hf | (43/2+) | | |-id=Hafnium-180 | ¹⁸⁰Hf | style="text-align:right" | 72 | style="text-align:right" | 108 | 179.9465595(15) | colspan=3 align=center|Observationally Stable | 0+ | 0.3508(33) | |-id=Hafnium-180m1 | rowspan=2 style="text-indent:1em" | ^180m1Hf | rowspan=2 colspan="3" style="text-indent:2em" | 1141.552(15)&nbsp;keV | rowspan=2|5.53(2)&nbsp;h | IT (99.69%) | ¹⁸⁰Hf | rowspan=2|8− | rowspan=2| | rowspan=2| |- | β^− (0.31%) | ^180m1Ta |-id=Hafnium-180m2 | style="text-indent:1em" | ^180m2Hf | colspan="3" style="text-indent:2em" | 1374.36(4)&nbsp;keV | 570(20)&nbsp;μs | IT | ¹⁸⁰Hf | 4− | | |-id=Hafnium-180m3 | style="text-indent:1em" | ^180m3Hf | colspan="3" style="text-indent:2em" | 2485.5(5)&nbsp;keV | 0.94(11)&nbsp;μs | IT | ¹⁸⁰Hf | 12+ | | |-id=Hafnium-180m4 | style="text-indent:1em" | ^180m4Hf | colspan="3" style="text-indent:2em" | 3599.0(10)&nbsp;keV | 90(10)&nbsp;μs | IT | ¹⁸⁰Hf | (18−) | | |-id=Hafnium-181 | ¹⁸¹Hf | style="text-align:right" | 72 | style="text-align:right" | 109 | 180.9491108(15) | 42.39(6)&nbsp;d | β^− | ¹⁸¹Ta | 1/2− | | |-id=Hafnium-181m1 | style="text-indent:1em" | ^181m1Hf | colspan="3" style="text-indent:2em" | 595.27(4)&nbsp;keV | 80(5)&nbsp;μs | IT | ¹⁸¹Hf | (9/2+) | | |-id=Hafnium-181m2 | style="text-indent:1em" | ^181m2Hf | colspan="3" style="text-indent:2em" | 1043.5(8)&nbsp;keV | ~100&nbsp;μs | IT | ¹⁸¹Hf | (17/2+) | | |-id=Hafnium-181m3 | style="text-indent:1em" | ^181m3Hf | colspan="3" style="text-indent:2em" | 1741.9(13)&nbsp;keV | 1.5(5)&nbsp;ms | IT | ¹⁸¹Hf | (25/2−) | | |-id=Hafnium-182 | ¹⁸²Hf | style="text-align:right" | 72 | style="text-align:right" | 110 | 181.9505637(66) | 8.90(9)×10⁶&nbsp;y | β^− | ¹⁸²Ta | 0+ | | |-id=Hafnium-182m1 | rowspan=2 style="text-indent:1em" | ^182m1Hf | rowspan=2 colspan="3" style="text-indent:2em" | 1172.87(18)&nbsp;keV | rowspan=2|61.5(15)&nbsp;min | β^− (54%) | ¹⁸²Ta | rowspan=2|8− | rowspan=2| | rowspan=2| |- | IT (46%) | ¹⁸²Hf |-id=Hafnium-182m2 | style="text-indent:1em" | ^182m2Hf | colspan="3" style="text-indent:2em" | 2571.3(12)&nbsp;keV | 40(10)&nbsp;μs | IT | ¹⁸²Hf | (13+) | | |-id=Hafnium-183 | ¹⁸³Hf | style="text-align:right" | 72 | style="text-align:right" | 111 | 182.953533(32) | 1.018(2)&nbsp;h | β^− | ¹⁸³Ta | (3/2−) | | |-id=Hafnium-183m | style="text-indent:1em" | ^183mHf | colspan="3" style="text-indent:2em" | 1464(64)&nbsp;keV | 40(30)&nbsp;s | IT | ¹⁸³Hf | 27/2−# | | |-id=Hafnium-184 | ¹⁸⁴Hf | style="text-align:right" | 72 | style="text-align:right" | 112 | 183.955449(43) | 4.12(5)&nbsp;h | β^− | ¹⁸⁴Ta | 0+ | | |-id=Hafnium-184m1 | style="text-indent:1em" | ^184m1Hf | colspan="3" style="text-indent:2em" | 1272.2(4)&nbsp;keV | 48(10)&nbsp;s | IT | ¹⁸⁴Hf | 8− | | |-id=Hafnium-184m2 | style="text-indent:1em" | ^184m2Hf | colspan="3" style="text-indent:2em" | 2477(10)&nbsp;keV | 16(7)&nbsp;min | | | 15+# | | |-id=Hafnium-185 | ¹⁸⁵Hf | style="text-align:right" | 72 | style="text-align:right" | 113 | 184.958862(69) | 3.5(6)&nbsp;min | β^− | ¹⁸⁵Ta | (9/2−) | | |-id=Hafnium-186 | ¹⁸⁶Hf | style="text-align:right" | 72 | style="text-align:right" | 114 | 185.960897(55) | 2.6(12)&nbsp;min | β^− | ¹⁸⁶Ta | 0+ | | |-id=Hafnium-186m | style="text-indent:1em" | ^186mHf | colspan="3" style="text-indent:2em" | 2968(43)&nbsp;keV | >20&nbsp;s | | | 17+# | | |-id=Hafnium-187 | ¹⁸⁷Hf | style="text-align:right" | 72 | style="text-align:right" | 115 | 186.96457(22)# | 14#&nbsp;s<br />[>300&nbsp;ns] | | | 9/2−# | | |-id=Hafnium-187m | style="text-indent:1em" | ^187mHf | colspan="3" style="text-indent:2em" | 500(300)#&nbsp;keV | 270(80)&nbsp;ns | IT | ¹⁸⁷Hf | 3/2−# | | |-id=Hafnium-188 | ¹⁸⁸Hf | style="text-align:right" | 72 | style="text-align:right" | 116 | 187.96690(32)# | 7#&nbsp;s<br />[>300&nbsp;ns] | | | 0+ | | |-id=Hafnium-189 | ¹⁸⁹Hf | style="text-align:right" | 72 | style="text-align:right" | 117 | 188.97085(32)# | 400#&nbsp;ms<br />[>300&nbsp;ns] | | | 3/2−# | | |-id=Hafnium-190 | ¹⁹⁰Hf | style="text-align:right" | 72 | style="text-align:right" | 118 | 189.97338(43)# | 600#&nbsp;ms<br />[>300&nbsp;ns] | | | 0+ | | |-id=Hafnium-191 | ¹⁹¹Hf | style="text-align:right" | 72 | style="text-align:right" | 119 | | | | | | | |-id=Hafnium-192 | ¹⁹²Hf | style="text-align:right" | 72 | style="text-align:right" | 120 | | | | | 0+ | |

See also

Daughter products other than hafnium

• Isotopes of tantalum
• Isotopes of lutetium
• Isotopes of ytterbium

References