Isotopes of dysprosium

Naturally occurring dysprosium (₆₆Dy) is composed of 7 stable isotopes, ¹⁵⁶Dy, ¹⁵⁸Dy, ¹⁶⁰Dy, ¹⁶¹Dy, ¹⁶²Dy, ¹⁶³Dy and ¹⁶⁴Dy, with ¹⁶⁴Dy being the most abundant (28.26% natural abundance). Twenty-nine radioisotopes have been characterized, with the most stable being ¹⁵⁴Dy with a half-life of 1.4 million years, ¹⁵⁹Dy with a half-life of 144.4 days, and ¹⁶⁶Dy with a half-life of 81.6 hours. All of the remaining radioactive isotopes have half-lives that are less than 10 hours, and the majority of these have half-lives that are less than 30 seconds. This element also has 12 meta states, with the most stable being ^165mDy (half-life 1.257 minutes), ^147mDy (half-life 55.7 seconds) and ^145mDy (half-life 13.6 seconds).

The primary decay mode before the most abundant stable isotope, ¹⁶⁴Dy, is electron capture to isotopes of terbium, and after beta decay to those of holmium. Dysprosium is the heaviest element to have isotopes that are theoretically stable (163, 164), rather than only ones that are observationally stable and predicted to be radioactive. ¹⁶⁴Dy has a surprisingly large thermal neutron absorption and the product isotope ¹⁶⁵Dy has found medical use (see below).

List of isotopes

|-id=Dysprosium-138 | ¹³⁸Dy | style="text-align:right" | 66 | style="text-align:right" | 72 | 137.96250(54)# | 200#&nbsp;ms<br>[>310&nbsp;ns] | | | 0+ | | |-id=Dysprosium-139 | rowspan=2|¹³⁹Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 73 | rowspan=2|138.95953(54)# | rowspan=2|600(200)&nbsp;ms | β⁺ (~89%) | ¹³⁹Tb | rowspan=2|(7/2+) | rowspan=2| | rowspan=2| |- | β⁺, p (~11%) | ¹³⁸Gd |-id=Dysprosium-140 | rowspan=2|¹⁴⁰Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 74 | rowspan=2|139.95402(43)# | rowspan=2|700#&nbsp;ms | β⁺? | ¹⁴⁰Tb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹³⁹Gd |-id=Dysprosium-140m | style="text-indent:1em" | ^140mDy | colspan="3" style="text-indent:2em" | 2166.1(5)&nbsp;keV | 7.0(5)&nbsp;μs | IT | ¹⁴⁰Dy | 8− | | |-id=Dysprosium-141 | rowspan=2|¹⁴¹Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 75 | rowspan=2|140.95128(32)# | rowspan=2|0.90(14)&nbsp;s | β⁺ | ¹⁴¹Tb | rowspan=2|(9/2−) | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹⁴⁰Gd |-id=Dysprosium-142 | rowspan=3|¹⁴²Dy | rowspan=3 style="text-align:right" | 66 | rowspan=3 style="text-align:right" | 76 | rowspan=3|141.94619(78)# | rowspan=3|2.3(3)&nbsp;s | β⁺ (90%) | rowspan=2|¹⁴²Tb | rowspan=3|0+ | rowspan=3| | rowspan=3| |- | EC (10%) |- | β⁺, p (0.06%) | ¹⁴¹Gd |-id=Dysprosium-143 | rowspan=2|¹⁴³Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 77 | rowspan=2|142.943994(14) | rowspan=2|5.6(10)&nbsp;s | β⁺ | ¹⁴³Tb | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹⁴²Gd |-id=Dysprosium-143m1 | rowspan=2 style="text-indent:1em" | ^143m1Dy | rowspan=2 colspan="3" style="text-indent:2em" | 310.7(6)&nbsp;keV | rowspan=2|3.0(3)&nbsp;s | β⁺ | ¹⁴³Tb | rowspan=2|(11/2−) | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹⁴²Gd |-id=Dysprosium-143m2 | style="text-indent:1em" | ^143m2Dy | colspan="3" style="text-indent:2em" | 406.3(8)&nbsp;keV | 1.2(3)&nbsp;μs | IT | ¹⁴³Dy | (7/2−) | | |-id=Dysprosium-144 | rowspan=2|¹⁴⁴Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 78 | rowspan=2|143.9392695(77) | rowspan=2|9.1(4)&nbsp;s | β⁺ | ¹⁴⁴Tb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹⁴³Gd |-id=Dysprosium-145 | rowspan=2|¹⁴⁵Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 79 | rowspan=2|144.9374740(70) | rowspan=2|9.5(10)&nbsp;s | β⁺ | ¹⁴⁵Tb | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | β⁺, p? | ¹⁴⁴Gd |-id=Dysprosium-145m | rowspan=2 style="text-indent:1em" | ^145mDy | rowspan=2 colspan="3" style="text-indent:2em" | 118.2(2)&nbsp;keV | rowspan=2|14.1(7)&nbsp;s | β⁺ | ¹⁴⁵Tb | rowspan=2|(11/2−) | rowspan=2| | rowspan=2| |- | β⁺, p (~50%) | ¹⁴⁴Gd |-id=Dysprosium-146 | ¹⁴⁶Dy | style="text-align:right" | 66 | style="text-align:right" | 80 | 145.9328445(72) | 33.2(7)&nbsp;s | β⁺ | ¹⁴⁶Tb | 0+ | | |-id=Dysprosium-146m | style="text-indent:1em" | ^146mDy | colspan="3" style="text-indent:2em" | 2934.5(4)&nbsp;keV | 150(20)&nbsp;ms | IT | ¹⁴⁶Dy | 10+ | | |-id=Dysprosium-147 | rowspan=2|¹⁴⁷Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 81 | rowspan=2|146.9310827(95) | rowspan=2|67(7)&nbsp;s | β⁺ (99.95%) | ¹⁴⁷Tb | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | β⁺, p (0.05%) | ¹⁴⁶Gd |-id=Dysprosium-147m1 | rowspan=2 style="text-indent:1em" | ^147m1Dy | rowspan=2 colspan="3" style="text-indent:2em" | 750.5(4)&nbsp;keV | rowspan=2|55.2(5)&nbsp;s | β⁺ (68.9%) | ¹⁴⁷Tb | rowspan=2|(11/2−) | rowspan=2| | rowspan=2| |- | IT (31.1%) | ¹⁴⁷Dy |-id=Dysprosium-147m2 | style="text-indent:1em" | ^147m2Dy | colspan="3" style="text-indent:2em" | 3407.2(8)&nbsp;keV | 0.40(1)&nbsp;μs | IT | ¹⁴⁷Dy | (27/2−) | | |-id=Dysprosium-148 | ¹⁴⁸Dy | style="text-align:right" | 66 | style="text-align:right" | 82 | 147.9271499(94) | 3.3(2)&nbsp;min | β⁺ | ¹⁴⁸Tb | 0+ | | |-id=Dysprosium-148m | style="text-indent:1em" | ^148mDy | colspan="3" style="text-indent:2em" | 2919.1(10)&nbsp;keV | 471(20)&nbsp;ns | IT | ¹⁴⁸Dy | 10+ | | |-id=Dysprosium-149 | ¹⁴⁹Dy | style="text-align:right" | 66 | style="text-align:right" | 83 | 148.9273275(99) | 4.20(14)&nbsp;min | β⁺ | ¹⁴⁹Tb | 7/2− | | |-id=Dysprosium-149m | rowspan=2 style="text-indent:1em" | ^149mDy | rowspan=2 colspan="3" style="text-indent:2em" | 2661.1(4)&nbsp;keV | rowspan=2|490(15)&nbsp;ms | IT (99.3%) | ¹⁴⁹Dy | rowspan=2|27/2− | rowspan=2| | rowspan=2| |- | β⁺ (0.7%) | ¹⁴⁹Tb |-id=Dysprosium-150 | rowspan=2|¹⁵⁰Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 84 | rowspan=2|149.9255931(46) | rowspan=2|7.17(5)&nbsp;min | β⁺ (66.4%) | ¹⁵⁰Tb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (33.6%) | ¹⁴⁶Gd |-id=Dysprosium-151 | rowspan=2|¹⁵¹Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 85 | rowspan=2|150.9261913(35) | rowspan=2|17.9(3)&nbsp;min | β⁺ (94.4%) | ¹⁵¹Tb | rowspan=2|7/2− | rowspan=2| | rowspan=2| |- | α (5.6%) | ¹⁴⁷Gd |-id=Dysprosium-152 | rowspan=2|¹⁵²Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 86 | rowspan=2|151.9247253(49) | rowspan=2|2.38(2)&nbsp;h | EC (99.90%) | ¹⁵²Tb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (0.100%) | ¹⁴⁸Gd |-id=Dysprosium-153 | rowspan=2|¹⁵³Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 87 | rowspan=2|152.9257717(43) | rowspan=2|6.4(1)&nbsp;h | β⁺ (99.99%) | ¹⁵³Tb | rowspan=2|7/2− | rowspan=2| | rowspan=2| |- | α (0.0094%) | ¹⁴⁹Gd |-id=Dysprosium-154 |¹⁵⁴Dy | style="text-align:right" | 66 |style="text-align:right" | 88 |153.9244289(80) |1.40(8)×10⁶&nbsp;y | α | ¹⁵⁰Gd |0+ | | |-id=Dysprosium-155 | ¹⁵⁵Dy | style="text-align:right" | 66 | style="text-align:right" | 89 | 154.925758(10) | 9.9(2)&nbsp;h | β⁺ | ¹⁵⁵Tb | 3/2− | | |-id=Dysprosium-155m | style="text-indent:1em" | ^155mDy | colspan="3" style="text-indent:2em" | 234.33(3)&nbsp;keV | 6(1)&nbsp;μs | IT | ¹⁵⁵Dy | 11/2− | | |-id=Dysprosium-156 | ¹⁵⁶Dy | style="text-align:right" | 66 | style="text-align:right" | 90 | 155.9242836(11) | colspan=3 align=center|Observationally Stable | 0+ | 5.6(3)×10^{−4} | |-id=Dysprosium-157 | ¹⁵⁷Dy | style="text-align:right" | 66 | style="text-align:right" | 91 | 156.9254696(55) | 8.14(4)&nbsp;h | β⁺ | ¹⁵⁷Tb | 3/2− | | |-id=Dysprosium-157m1 | style="text-indent:1em" | ^157m1Dy | colspan="3" style="text-indent:2em" | 161.99(3)&nbsp;keV | 1.3(2)&nbsp;μs | IT | ¹⁵⁷Dy | 9/2+ | | |-id=Dysprosium-157m2 | style="text-indent:1em" | ^157m2Dy | colspan="3" style="text-indent:2em" | 199.38(7)&nbsp;keV | 21.6(16)&nbsp;ms | IT | ¹⁵⁷Dy | 11/2− | | |-id=Dysprosium-158 | ¹⁵⁸Dy | style="text-align:right" | 66 | style="text-align:right" | 92 | 157.9244148(25) | colspan=3 align=center|Observationally Stable | 0+ | 9.5(3)×10^{−4} | |-id=Dysprosium-159 | ¹⁵⁹Dy | style="text-align:right" | 66 | style="text-align:right" | 93 | 158.9257459(15) | 144.4(2)&nbsp;d | EC | ¹⁵⁹Tb | 3/2− | | |-id=Dysprosium-159m | style="text-indent:1em" | ^159mDy | colspan="3" style="text-indent:2em" | 352.77(14)&nbsp;keV | 122(3)&nbsp;μs | IT | ¹⁵⁹Dy | 11/2− | | |-id=Dysprosium-160 | ¹⁶⁰Dy | style="text-align:right" | 66 | style="text-align:right" | 94 | 159.92520358(75) | colspan=3 align=center|Observationally Stable | 0+ | 0.02329(18) | |-id=Dysprosium-161 | ¹⁶¹Dy | style="text-align:right" | 66 | style="text-align:right" | 95 | 160.92693943(75) | colspan=3 align=center|Observationally Stable | 5/2+ | 0.18889(42) | |-id=Dysprosium-161m | style="text-indent:1em" | ^161mDy | colspan="3" style="text-indent:2em" | 485.56(16)&nbsp;keV | 0.76(17)&nbsp;μs | IT | ¹⁶¹Dy | 11/2− | | |-id=Dysprosium-162 | ¹⁶²Dy | style="text-align:right" | 66 | style="text-align:right" | 96 | 161.92680451(75) | colspan=3 align=center|Observationally Stable | 0+ | 0.25475(36) | |-id=Dysprosium-162m | style="text-indent:1em" | ^162mDy | colspan="3" style="text-indent:2em" | 2188.1(3)&nbsp;keV | 8.3(3)&nbsp;μs | IT | ¹⁶²Dy | 8+ | | |-id=Dysprosium-163 | ¹⁶³Dy | style="text-align:right" | 66 | style="text-align:right" | 97 | 162.92873722(74) | colspan=3 align=center|Stable | 5/2− | 0.24896(42) | |-id=Dysprosium-164 | ¹⁶⁴Dy | style="text-align:right" | 66 | style="text-align:right" | 98 | 163.92918082(75) | colspan=3 align=center|Stable | 0+ | 0.28260(54) | |- | ¹⁶⁵Dy | style="text-align:right" | 66 | style="text-align:right" | 99 | 164.93170940(75) | 2.332(4)&nbsp;h | β^− | ¹⁶⁵Ho | 7/2+ | | |-id=Dysprosium-165m | rowspan=2 style="text-indent:1em" | ^165mDy | rowspan=2 colspan="3" style="text-indent:2em" | 108.1552(13)&nbsp;keV | rowspan=2|1.257(6)&nbsp;min | IT (97.76%) | ¹⁶⁵Dy | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | β^− (2.24%) | ¹⁶⁵Ho |-id=Dysprosium-166 | ¹⁶⁶Dy | style="text-align:right" | 66 | style="text-align:right" | 100 | 165.93281281(86) | 81.6(1)&nbsp;h | β^− | ¹⁶⁶Ho | 0+ | | |-id=Dysprosium-167 | ¹⁶⁷Dy | style="text-align:right" | 66 | style="text-align:right" | 101 | 166.9356824(43) | 6.20(8)&nbsp;min | β^− | ¹⁶⁷Ho | (1/2−) | | |-id=Dysprosium-168 | ¹⁶⁸Dy | style="text-align:right" | 66 | style="text-align:right" | 102 | 167.93713(15) | 8.7(3)&nbsp;min | β^− | ¹⁶⁸Ho | 0+ | | |-id=Dysprosium-168m | style="text-indent:1em" | ^168mDy | colspan="3" style="text-indent:2em" | 1378.2(6)&nbsp;keV | 0.57(7)&nbsp;μs | IT | ¹⁶⁸Dy | (4−) | | |-id=Dysprosium-169 | ¹⁶⁹Dy | style="text-align:right" | 66 | style="text-align:right" | 103 | 168.94032(32) | 39(8)&nbsp;s | β^− | ¹⁶⁹Ho | (5/2)− | | |-id=Dysprosium-169m | style="text-indent:1em" | ^169mDy | colspan="3" style="text-indent:2em" | 166.1(5)&nbsp;keV | 1.26(17)&nbsp;μs | IT | ¹⁶⁹Dy | (1/2−) | | |-id=Dysprosium-170 | ¹⁷⁰Dy | style="text-align:right" | 66 | style="text-align:right" | 104 | 169.94234(22)# | 54.9(80)&nbsp;s | β^− | ¹⁷⁰Ho | 0+ | | |-id=Dysprosium-170m | style="text-indent:1em" | ^170mDy | colspan="3" style="text-indent:2em" | 1643.8(3)&nbsp;keV | 0.99(4)&nbsp;μs | IT | ¹⁷⁰Dy | (6+) | | |-id=Dysprosium-171 | ¹⁷¹Dy | style="text-align:right" | 66 | style="text-align:right" | 105 | 170.94631(22)# | 4.07(40)&nbsp;s | β^− | ¹⁷¹Ho | 7/2−# | | |-id=Dysprosium-172 | ¹⁷²Dy | style="text-align:right" | 66 | style="text-align:right" | 106 | 171.94873(32)# | 3.4(2)&nbsp;s | β^− | ¹⁷²Ho | 0+ | | |-id=Dysprosium-172m | rowspan=2 style="text-indent:1em" | ^172mDy | rowspan=2 colspan="3" style="text-indent:2em" | 1278(1)&nbsp;keV | rowspan=2|710(50)&nbsp;ms | IT (81%) | ¹⁷²Dy | rowspan=2|(8−) | rowspan=2| | rowspan=2| |- | β^− (19%) | ¹⁷²Ho |-id=Dysprosium-173 | rowspan=2|¹⁷³Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 107 | rowspan=2|172.95304(43)# | rowspan=2|1.43(20)&nbsp;s | β^− | ¹⁷³Ho | rowspan=2|9/2+# | rowspan=2| | rowspan=2| |- | β^−, n? | ¹⁷²Ho |-id=Dysprosium-174 | rowspan=2|¹⁷⁴Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 108 | rowspan=2|173.95585(54)# | rowspan=2|1#&nbsp;s<br>[>300&nbsp;ns] | β^−? | ¹⁷⁴Ho | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β^−, n? | ¹⁷³Ho |-id=Dysprosium-175 | rowspan=2|¹⁷⁵Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 109 | rowspan=2|174.96057(54)# | rowspan=2|390#&nbsp;ms<br>[>550&nbsp;ns] | β^−? | ¹⁷⁵Ho | rowspan=2|1/2-# | rowspan=2| | rowspan=2| |- | β^−, n? | ¹⁷⁴Ho |-id=Dysprosium-176 | rowspan=2|¹⁷⁶Dy | rowspan=2 style="text-align:right" | 66 | rowspan=2 style="text-align:right" | 110 | rowspan=2|175.96392(54)# | rowspan=2|440#&nbsp;ms<br>[>550&nbsp;ns] | β^−? | ¹⁷⁶Ho | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β^−, n? | ¹⁷⁵Ho

Dysprosium-165

The radioactive isotope ¹⁶⁵Dy, with a half-life of 2.332 hours, has radiopharmaceutical uses in radiation synovectomy of the knee. It had been previously performed with colloidal-sized particles containing longer-lived isotopes such as ¹⁹⁸Au and ⁹⁰Y. The major problem with the usage of those isotopes was radiation leakage out of the knee. ¹⁶⁵Dy, with its shorter half-life and thus shorter period of potential radiation leakage, is more suitable for the procedure.

See also

Daughter products other than dysprosium

• Isotopes of holmium
• Isotopes of terbium
• Isotopes of gadolinium

References