Samarium: isotope data

Samarium isotopes are used in various applications. Sm-144 is used for the production of the therapeutic radioisotope Sm-145. Sm-147 has been bombarded with Ca-40 to produce the short-lived radioisotopes Pb-182. Sm-148 has been used to study the giant monopole resonance while Sm-149 has been used in a filter for polarizing thermal neutrons. Sm-152 is used for the production of the radioisotope Sm-153 which is used for bone pain palliation. Finally, Sm-154 has been used to study the excited states of Sm-153.

Naturally occurring isotopes

This table shows information about naturally occuring isotopes, their atomic masses, their natural abundances, their nuclear spins, and their magnetic moments. Further data for radioisotopes (radioactive isotopes) of samarium are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
144Sm 143.911998 (4) 3.07 (7) 0
147Sm 146.914894 (4) 14.99 (18) 7/2 -0.8149
148Sm 147.914819 (4) 11.24 (10) 0
149Sm 148.917180 (4) 13.82 (7) 7/2 -0.6718
150Sm 149.917273 (4) 7.38 (1) 0
152Sm 151.919728 (4) 26.75 (16) 0
154Sm 153.922205 (4) 22.75 (29) 0

In the above, the most intense ion is set to 100% since this corresponds best to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.

Radiosotope data

Further data for naturally occuring isotopes of samarium are listed above. This table gives information about some radiosotopes of samarium, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass / Da Half-life Mode of decay Nuclear spin Nuclear magnetic moment
145Sm 144.913407 340 d EC to 145Pm 7/2 -1.1
146Sm 145.913038 1.03 x 108 y α to 142Nd 0
151Sm 150.919929 90 y β- to 151Eu 5/2 -0.363
153Sm 152.922094 1.929 d β- to 153Eu 3/2 -0.0216
155Sm 154.924636 22.2 m β- to 155Eu 3/2
156Sm 155.92553 9.4 h β- to 156Eu 0

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  1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1998 IUPAC]
  2. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides
  3. Masses, nuclear spins, and magnetic moments: I. Mills, T. Cvitas, K. Homann, N. Kallay, and K. Kuchitsu in Quantities, Units and Symbols in Physical Chemistry, Blackwell Scientific Publications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

NMR Properties of samarium

Common reference compound: .

Table of NMR-active nucleus propeties of samarium
  Isotope 1 Isotope 2 Isotope 3
Isotope 147Sm 149Sm
Natural abundance /% 15.0 13.8
Spin (I) 7/2 7/2
Frequency relative to 1H = 100 (MHz) about 4.17 about 3.44
Receptivity, DP, relative to 1H = 1.00 - -
Receptivity, DC, relative to 13C = 1.00 - -
Magnetogyric ratio, γ (107 rad T‑1 s-1) -1.115 -0.9192
Magnetic moment, μ (μN) -0.9239 -0.7616
Nuclear quadrupole moment, Q/millibarn -259(26) +75(8) and +1014(93) [Mössbauer state]
Line width factor, 1056 l (m4)


  1. R.K. Harris in Encyclopedia of Nuclear Magnetic Resonance, D.M. Granty and R.K. Harris, (eds.), vol. 5, John Wiley & Sons, Chichester, UK, 1996. I am grateful to Professor Robin Harris (University of Durham, UK) who provided much of the NMR data, which are copyright 1996 IUPAC, adapted from his contribution contained within this reference.
  2. J. Mason in Multinuclear NMR, Plenum Press, New York, USA, 1987. Where given, data for certain radioactive nuclei are from this reference.
  3. P. Pyykkö, Mol. Phys., 2008, 106, 1965-1974.
  4. P. Pyykkö, Mol. Phys., 2001, 99, 1617-1629.
  5. P. Pyykkö, Z. Naturforsch., 1992, 47a, 189. I am grateful to Professor Pekka Pyykkö (University of Helsinki, Finland) who provided the nuclear quadrupole moment data in this and the following two references.
  6. D.R. Lide, (ed.), CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, USA, 79th edition, 1998.
  7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.

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