More Chemistry
All atomic nuclei of the chemical element samarium are summarized under samarium isotopes; these all consist of an atomic nucleus with 62 protons and, in the uncharged state, 62 electrons. The difference between each samarium isotope is based on the number of neutrons in the nucleus.
Samarium, a chemical element from the group of rare earth metals, occurs naturally in a large number of isotopes, 5 of which are considered stable and 3 of which have half-lives of many millions of years.
Atomic Mass ma | Quantity | Half-life | Spin | |
Samarium Isotopic mixture | 150,36 u | 100 % | ||
Isotope 144Sm | 143,91201(2) u | 3,08(4) % | stable | 0+ |
Isotope 146Sm | 145,913047(3) u | traces | 6.8(7) × 107 a | 0+ |
Isotope 148Sm | 147,91483(2) u | 11,25(9) % | 7(3)×1015 a | 0+ |
Isotope 149Sm | 148,91719(2) u | 13,82(10) % | stable | 7/2- |
Isotope 150Sm | 149,91728(2) u | 7,37(9) % | stable | 0+ |
Isotope 152Sm | 151,91974(2) u | 26,74(9) % | stable | 0+ |
Isotope 154Sm | 153,92222(2) u | 22,74(14) % | stable | 0+ |
Isotope 147Sm | 146,91490(2) u | 15,00(14) % | 1.0625(38) × 1011 a | 7/2- |
All other samarium nuclides are unstable and decay, emitting radioactive radiation.
The samarium nuclide 153 is used in nuclear medicine. sup>Sm Application as anti-inflammatory radiotherapeutic agent [153Sm]samarium hydroxyapatite colloid (ATC code V10AX02) and as [153Sm]samarium lexidronam (V10BX02) for pain relief in bone metastases.
Isotope Nuclide | E | N | Atomic Mass [Nuclear Mass] {Mass Excess} | Spin I (h/2π) | Parent |
---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 |
Samarium-128 | 12862Sm | 66 | 127.95808(54) u [127.9240707 u] {-39.04823 MeV} | 0+ | |
Samarium-129 | 12962Sm | 67 | 128.95491(54) u [128.9209007 u] {-42.00106 MeV} | (1/2+,3/2+) | |
Samarium-130 | 13062Sm | 68 | 129.94900(43) u [129.9149907 u] {-47.50619 MeV} | 0+ | 130Eu |
Samarium-131 | 13162Sm | 69 | 130.94618(43) u [130.9121707 u] {-50.13301 MeV} | 5/2+~ | 131Eu |
Samarium-132 | 13262Sm | 70 | 131.94087(32) u [131.9068607 u] {-55.07924 MeV} | 0+ | 132Eu |
Samarium-133 | 13362Sm | 71 | 132.93856(32) u [132.9045507 u] {-57.23099 MeV} | (5/2+) | 133Eu |
Samarium-134 | 13462Sm | 72 | 133.93411(21) u [133.9001007 u] {-61.37614 MeV} | 0+ | 134Eu |
Samarium-135 | 13562Sm | 73 | 134.93252(17) u [134.8985107 u] {-62.85722 MeV} | (3/2+,5/2+) | 135Eu |
Samarium-135m | 135m62Sm | 73 | 134.93252(17) u [134.8985107 u] {-62.85722 MeV} | ||
Samarium-136 | 13662Sm | 74 | 135.928276(13) u [135.8942667 u] {-66.81048 MeV} | 0+ | 136Eu |
Samarium-136m | 136m62Sm | 74 | 135.928276(13) u [135.8942667 u] {-66.81048 MeV} | (8-) | |
Samarium-137 | 13762Sm | 75 | 136.92697(5) u [136.8929607 u] {-68.02701 MeV} | (9/2-) | 137Eu |
Samarium-137m | 137m62Sm | 75 | 136.92697(5) u [136.8929607 u] {-68.02701 MeV} | (1/2+) | |
Samarium-138 | 13862Sm | 76 | 137.923244(13) u [137.8892347 u] {-71.49775 MeV} | 0+ | 138Eu |
Samarium-139 | 13962Sm | 77 | 138.922297(12) u [138.8882877 u] {-72.37988 MeV} | 1/2+ | 139Eu |
Samarium-139m | 139m62Sm | 77 | 138.922297(12) u [138.8882877 u] {-72.37988 MeV} | 11/2- | |
Samarium-140 | 14062Sm | 78 | 139.918995(13) u [139.8849857 u] {-75.45567 MeV} | 0+ | 140Eu |
Samarium-141 | 14162Sm | 79 | 140.918482(9) u [140.8844727 u] {-75.93353 MeV} | 1/2+ | 141Eu |
Samarium-141m | 141m62Sm | 79 | 140.918482(9) u [140.8844727 u] {-75.93353 MeV} | 11/2- | |
Samarium-142 | 14262Sm | 80 | 141.915205(3) u [141.8811957 u] {-78.98603 MeV} | 0+ | 142Eu |
Samarium-143 | 14362Sm | 81 | 142.914635(3) u [142.8806257 u] {-79.51699 MeV} | 3/2+ | 143Eu |
Samarium-143m1 | 143m162Sm | 81 | 142.914635(3) u [142.8806257 u] {-79.51699 MeV} | 11/2- | |
Samarium-143m2 | 143m262Sm | 81 | 142.914635(3) u [142.8806257 u] {-79.51699 MeV} | 23/2(-) | |
Samarium-144 | 14462Sm | 82 | 143.91201(2) u [143.8780007 u] {-81.96216 MeV} | 0+ | 144Eu 144Pm 148Gd |
Samarium-144m | 144m62Sm | 82 | 143.91201(2) u [143.8780007 u] {-81.96216 MeV} | 6+ | |
Samarium-145 | 14562Sm | 83 | 144.9134172(17) u [144.8794079 u] {-80.65136 MeV} | 7/2- | 145Eu 149Gd |
Samarium-145m | 145m62Sm | 83 | 144.9134172(17) u [144.8794079 u] {-80.65136 MeV} | (49/2+) | |
Samarium-146 | 14662Sm | 84 | 145.913047(3) u [145.8790377 u] {-80.9962 MeV} | 0+ | 146Eu 146Pm 150Gd |
Samarium-147 | 14762Sm | 85 | 146.91490(2) u [146.8808907 u] {-79.27014 MeV} | 7/2- | 147Eu 147Pm 151Gd |
Samarium-148 | 14862Sm | 86 | 147.91483(2) u [147.8808207 u] {-79.33534 MeV} | 0+ | 148Eu 148Pm 152Gd |
Samarium-149 | 14962Sm | 87 | 148.91719(2) u [148.8831807 u] {-77.13702 MeV} | 7/2- | 149Eu 149Pm |
Samarium-150 | 15062Sm | 88 | 149.91728(2) u [149.8832707 u] {-77.05318 MeV} | 0+ | 150Eu 150Pm 150Nd |
Samarium-151 | 15162Sm | 89 | 150.9199391(14) u [150.8859298 u] {-74.57625 MeV} | 5/2- | 151Pm |
Samarium-151m | 151m62Sm | 89 | 150.9199391(14) u [150.8859298 u] {-74.57625 MeV} | (11/2)- | |
Samarium-152 | 15262Sm | 90 | 151.91974(2) u [151.8857307 u] {-74.76171 MeV} | 0+ | 152Pm 152Eu |
Samarium-153 | 15362Sm | 91 | 152.9221036(11) u [152.8880943 u] {-72.56003 MeV} | 3/2+ | 153Pm |
Samarium-153m | 153m62Sm | 91 | 152.9221036(11) u [152.8880943 u] {-72.56003 MeV} | 11/2- | |
Samarium-154 | 15462Sm | 92 | 153.92222(2) u [153.8882107 u] {-72.4516 MeV} | 0+ | 154Pm 154Eu |
Samarium-155 | 15562Sm | 93 | 154.9246471(16) u [154.8906378 u] {-70.19077 MeV} | 3/2- | 155Pm |
Samarium-156 | 15662Sm | 94 | 155.925539(9) u [155.8915297 u] {-69.35997 MeV} | 0+ | 156Pm |
Samarium-156m | 156m62Sm | 94 | 155.925539(9) u [155.8915297 u] {-69.35997 MeV} | 5- | |
Samarium-157 | 15762Sm | 95 | 156.928419(5) u [156.8944097 u] {-66.67727 MeV} | (3/2-) | 157Pm |
Samarium-158 | 15862Sm | 96 | 157.929951(5) u [157.8959417 u] {-65.25022 MeV} | 0+ | 158Pm |
Samarium-159 | 15962Sm | 97 | 158.933217(6) u [158.8992077 u] {-62.20796 MeV} | 5/2- | 159Pm |
Samarium-160 | 16062Sm | 98 | 159.935335(6) u [159.9013257 u] {-60.23506 MeV} | 0+ | 160Pm |
Samarium-161 | 16162Sm | 99 | 160.939160(7) u [160.9051507 u] {-56.67209 MeV} | (7/2+) | 161Pm |
Samarium-162 | 16262Sm | 100 | 161.94146(21) u [161.9074507 u] {-54.52966 MeV} | 0+ | 162Pm |
Samarium-163 | 16362Sm | 101 | 162.94555(32) u [162.9115407 u] {-50.71985 MeV} | (1/2-) | 163Pm |
Samarium-164 | 16462Sm | 102 | 163.94836(32) u [163.9143507 u] {-48.10235 MeV} | 0+ | |
Samarium-165 | 16562Sm | 103 | 164.95297(43) u [164.9189607 u] {-43.80816 MeV} | (5/2-) | |
Samarium-166 | 16662Sm | 104 | 165.95627(43) u [165.9222607 u] {-40.73423 MeV} | 0+ |
Isotope | Radioactive Decay | Extern | |||
---|---|---|---|---|---|
Half-life | Decay Mode | Probability | Energy | ||
7 | 8 | 9 | 10 | 11 | 12 |
Sm-128 | 0.5 s | AL | |||
Sm-129 | 0.55(10) s | EC/β+ → 129Pm EC, p → 128Nd | < 100 % > 0 % | 10.88(58) MeV | AL |
Sm-130 | 1 s | EC/β+ → 130Pm | ? | 7.89(45) MeV | AL |
Sm-131 | 1.2(2) s | EC/β+ → 131Pm EC, p → 130Nd | 100 % ? | 9.53(45) MeV | AL |
Sm-132 | 4.0(3) s | EC/β+ → 132Pm EC, p → 131Nd | 100 % ? | 6.55(33) MeV | AL |
Sm-133 | 2.89(16) s | EC/β+ → 133Pm EC, p → 132Nd | 100 % ? | 8.818(30) MeV | AL |
Sm-134 | 9.5(8) s | EC/β+ → 134Pm | 100 % | 5.36(20) MeV | AL |
Sm-135 | 10.3(5) s | EC/β+ → 135Pm EC, p → 134Nd | 99.98 % 0.02(1) % | 7.19(17) MeV | AL |
Sm-135m | 2.4(9) s | β+ → 135Pm | AL | ||
Sm-136 | 47(2) s | EC/β+ → 136Pm | 100 % | 4.36(7) MeV | AL |
Sm-136m | 15(1) μs | AL | |||
Sm-137 | 45(1) s | EC/β+ → 137Pm | 100 % | 6.05(4) MeV | AL |
Sm-137m | 20 s | EC/β+ → 137Pm | AL | ||
Sm-138 | 3.1(2) min | EC/β+ → 138Pm | 100 % | 3.44(3) MeV | AL |
Sm-139 | 2.57(10) min | EC/β+ → 139Pm | 100 % | 5.120(17) MeV | AL |
Sm-139m | 10.7(6) s | Iso → 139Sm EC/β+ → 139Pm | 97.7(5) % 6.3(5) % | AL | |
Sm-140 | 14.82(12) min | EC/β+ → 140Pm | 100 % | 2.758(27) MeV | AL |
Sm-141 | 10.2(2) min | EC/β+ → 141Pm | 100 % | 4.589(16) MeV | AL |
Sm-141m | 22.6(2) min | EC/β+ → 141Pm Iso → 141Sm | 99.69(3) % 0.31(3) % | AL | |
Sm-142 | 72.49(5) min | EC/β+ → 142Pm | 100 % | 2.156(24) MeV | AL |
Sm-143 | 8.75(6) min | EC/β+ → 143Pm | 100 % | 3.443(4) MeV | AL |
Sm-143m1 | 66(2) s | Iso → 143Sm β+ → 143Pm | 99.76(5) % 0.24(5) % | AL | |
Sm-143m2 | 30(3) ms | Iso → 143Sm | 100 % | AL | |
Sm-144 | stable | AL | |||
Sm-144m | 880(25) ns | AL | |||
Sm-145 | 340(3) d | EC → 145Pm | 100 % | 0.616(3) MeV | AL |
Sm-145m | 0.96 μs | Iso → 145Sm | 100 % | AL | |
Sm-146 | 6.8(7) × 107 a | α → 142Nd | 100 % | 2.5288(28) MeV | AL |
Sm-147 | 1.0625(38) × 1011 a | α → 143Nd | 100 % | 2.3113(5) MeV | AL |
Sm-148 | 7(3)×1015 a | α → 144Nd | 100 % | 1.9868(4) MeV | AL |
Sm-149 | stable | AL | |||
Sm-150 | stable | AL | |||
Sm-151 | 90(8) a | β- → 151Eu | 100 % | 0.0766(5) MeV | AL |
Sm-151m | 1.4(1) μs | Iso → 151Sm | 100 % | AL | |
Sm-152 | stable | AL | |||
Sm-153 | 46.284(4) h | β- → 153Eu | 100 % | 0.8074(7) MeV | AL |
Sm-153m | 10.6(3) ms | Iso → 153Sm | 100 % | AL | |
Sm-154 | stable | AL | |||
Sm-155 | 22.3(2) min | β- → 155Eu | 100 % | 1.6273(12) MeV | AL |
Sm-156 | 9.4(2) h | β- → 156Eu | 100 % | 0.722(8) MeV | AL |
Sm-156m | 185(7) ns | AL | |||
Sm-157 | 8.03(7) min | β- → 157Eu | 100 % | 2.781(6) MeV | AL |
Sm-158 | 5.30(3) min | β- → 158Eu | 100 % | 2.005(10) MeV | AL |
Sm-159 | 11.37(15) s | β- → 159Eu | 100 % | 3.836(7) MeV | AL |
Sm-160 | 9.6(3) s | β- → 160Eu | 100 % | 3.246(11) MeV | AL |
Sm-161 | 4.8(4) s | β- → 161Eu | 100 % | 5.120(12) MeV | AL |
Sm-162 | 2.4(5) s | β- → 162Eu | 100 % | 4.17(20) MeV | AL |
Sm-163 | 1.23 s | β- → 163Eu β-, n → 162Eu | 100 % ? | 5.76(30) MeV | AL |
Sm-164 | 1.43(24) s | β- → 164Eu β-, n → 163Eu | 100 % ? | 5.28(32) MeV 0.31(30) MeV | AL |
Sm-165 | 0.98(21) s | β- → 165Eu β-, n → 164Eu | 100 % ? | 6.92(42) MeV 1.50(42) MeV | AL |
Sm-166 | 0.80(63) s | β- → 166Eu β-, n → 165Eu | 100 % ? | 6.48(54) MeV 1.92(42) 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 Samarium 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 Samarium 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) |
---|---|---|---|---|
147Sm 15,00(14) % 7/2- | -0,8090(14) | 1,1124 {- 0,259(26)} | 1,7748 | 0,00152 0,8754 |
149Sm 13,82(10) % 7/2- | - 0,6718 | 0,9175 {+ 0,75(7)} | 1,4631 | 0,00085 0,7216 |
1) Quantity Percentage of natural occurrence.
2) Gyromagnetic ratio: 107 rad T-1 s-1
Quadrupole moment: Q [barn] = [100 fm2]
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 Samarium radionuclides:
Nuclide | Limit Value | HASS limit | SC | Daughter Nuclides | Half-life | |
---|---|---|---|---|---|---|
Sm-141 | 105 Bq | 10 Bq/g | 10.2 min | |||
Sm-141m+ | 106 Bq | 10 Bq/g | 22.6 min | |||
Sm-142+ | 107 Bq | 100 Bq/g | 72.5 min | |||
Sm-145 | 107 Bq | 10 Bq/g | 340.0 d | |||
Sm-146 | 105 Bq | 1 Bq/g | 1 × 108 a | |||
Sm-147 | 104 Bq | 1 Bq/g | Unbegrenzt (UL) | 1.1 × 1011 a | ||
Sm-151 | 108 Bq | 1000 Bq/g | 500 TBq | 100 Bq cm-2 | 90.0 a | |
Sm-153 | 106 Bq | 100 Bq/g | 2 TBq | 10 Bq cm-2 | 46.3 h | |
Sm-155 | 106 Bq | 100 Bq/g | 22.3 min | |||
Sm-156 | 106 Bq | 100 Bq/g | 9.4 h |
(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)
Properties of the Samarium 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.
Samarium: NMR properties - 147Sm-NMR, 149Sm-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] - N. Kinoshita et al:
A Shorter 146Sm Half-Life Measured and Implications for 146Sm-142Nd Chronology in the Solar System.
In: Science, (2012), DOI 10.1126/science.1215510.
Last update: 2022-12-12
Perma link: https://www.chemlin.org/chemical-elements/samarium-isotopes.php
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