Isotopes of neodymium

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Naturally occurring neodymium (Nd) is composed of 5 stable isotopes, 142Nd, 143Nd, 145Nd, 146Nd and 148Nd, with 142Nd being the most abundant (27.2% natural abundance), and 2 radioisotopes, 144Nd and 150Nd. In all, 33 radioisotopes of Neodymium have been characterized up to now, with the most stable being naturally occurring isotopes 144Nd (alpha decay, a half-life (t1/2) of 2.29×1015 years) and 150Nd (double beta decay, t1/2 of 7×1018 years). All of the remaining radioactive isotopes have half-lives that are less than 11 days, and the majority of these have half-lives that are less than 70 seconds. This element also has 13 known meta states with the most stable being 139mNd (t1/2 5.5 hours), 135mNd (t1/2 5.5 minutes) and 133m1Nd (t1/2 ~70 seconds).

The primary decay modes before the most abundant stable isotope, 142Nd, are electron capture and positron decay, and the primary mode after is beta minus decay. The primary decay products before 142Nd are element Pr (praseodymium) isotopes and the primary products after are element Pm (promethium) isotopes.
Standard atomic mass: 144.242(3) u

Table[edit]

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life[n 1] decay
mode(s)[1][n 2]
daughter
isotope(s)[n 3]
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
124Nd 60 64 123.95223(64)# 500# ms 0+
125Nd 60 65 124.94888(43)# 600(150) ms 5/2(+#)
126Nd 60 66 125.94322(43)# 1# s [>200 ns] β+ 126Pr 0+
127Nd 60 67 126.94050(43)# 1.8(4) s β+ 127Pr 5/2+#
β+, p (rare) 126Ce
128Nd 60 68 127.93539(21)# 5# s β+ 128Pr 0+
β+, p (rare) 127Ce
129Nd 60 69 128.93319(22)# 4.9(2) s β+ 129Pr 5/2+#
β+, p (rare) 128Ce
130Nd 60 70 129.92851(3) 21(3) s β+ 130Pr 0+
131Nd 60 71 130.92725(3) 33(3) s β+ 131Pr (5/2)(+#)
β+, p (rare) 130Ce
132Nd 60 72 131.923321(26) 1.56(10) min β+ 132Pr 0+
133Nd 60 73 132.92235(5) 70(10) s β+ 133Pr (7/2+)
133m1Nd 127.97(11) keV ~70 s β+ 133Pr (1/2)+
133m2Nd 176.10(10) keV ~300 ns (9/2-)
134Nd 60 74 133.918790(13) 8.5(15) min β+ 134Pr 0+
134mNd 2293.1(4) keV 410(30) µs (8)-
135Nd 60 75 134.918181(21) 12.4(6) min β+ 135Pr 9/2(-)
135mNd 65.0(2) keV 5.5(5) min β+ 135Pr (1/2+)
136Nd 60 76 135.914976(13) 50.65(33) min β+ 136Pr 0+
137Nd 60 77 136.914567(12) 38.5(15) min β+ 137Pr 1/2+
137mNd 519.43(17) keV 1.60(15) s IT 137Nd (11/2-)
138Nd 60 78 137.911950(13) 5.04(9) h β+ 138Pr 0+
138mNd 3174.9(4) keV 410(50) ns (10+)
139Nd 60 79 138.911978(28) 29.7(5) min β+ 139Pr 3/2+
139m1Nd 231.15(5) keV 5.50(20) h β+ (88.2%) 139Pr 11/2-
IT (11.8%) 139Nd
139m2Nd 2570.9+X keV ≥141 ns
140Nd 60 80 139.90955(3) 3.37(2) d EC 140Pr 0+
140mNd 2221.4(1) keV 600(50) µs 7-
141Nd 60 81 140.909610(4) 2.49(3) h β+ 141Pr 3/2+
141mNd 756.51(5) keV 62.0(8) s IT (99.95%) 141Nd 11/2-
β+ (.05%) 141Pr
142Nd 60 82 141.9077233(25) Stable[n 4] 0+ 0.272(5) 0.2680-0.2730
143Nd[n 5][n 6] 60 83 142.9098143(25) Observationally Stable[n 7] 7/2- 0.122(2) 0.1212-0.1232
144Nd[n 5][n 8] 60 84 143.9100873(25) 2.29(16)×1015 a α 140Ce 0+ 0.238(3) 0.2379-0.2397
145Nd[n 5] 60 85 144.9125736(25) Observationally Stable[n 9] 7/2- 0.083(1) 0.0823-0.0835
146Nd[n 5] 60 86 145.9131169(25) Observationally Stable[n 10] 0+ 0.172(3) 0.1706-0.1735
147Nd[n 5] 60 87 146.9161004(25) 10.98(1) d β- 147Pm 5/2-
148Nd[n 5] 60 88 147.916893(3) Observationally Stable[n 11] 0+ 0.057(1) 0.0566-0.0578
149Nd[n 5] 60 89 148.920149(3) 1.728(1) h β- 149Pm 5/2-
150Nd[n 5][n 8] 60 90 149.920891(3) 6.7(7)×1018 a β-β- 150Sm 0+ 0.056(2) 0.0553-0.0569
151Nd 60 91 150.923829(3) 12.44(7) min β- 151Pm 3/2+
152Nd 60 92 151.924682(26) 11.4(2) min β- 152Pm 0+
153Nd 60 93 152.927698(29) 31.6(10) s β- 153Pm (3/2)-
154Nd 60 94 153.92948(12) 25.9(2) s β- 154Pm 0+
154m1Nd 480(150)# keV 1.3(5) µs
154m2Nd 1349(10) keV >1 µs (5-)
155Nd 60 95 154.93293(16)# 8.9(2) s β- 155Pm 3/2-#
156Nd 60 96 155.93502(22) 5.49(7) s β- 156Pm 0+
156mNd 1432(5) keV 135 ns 5-
157Nd 60 97 156.93903(21)# 2# s [>300 ns] β- 157Pm 5/2-#
158Nd 60 98 157.94160(43)# 700# ms [>300 ns] β- 158Pm 0+
159Nd 60 99 158.94609(54)# 500# ms β- 159Pm 7/2+#
160Nd 60 100 159.94909(64)# 300# ms β- 160Pm 0+
161Nd 60 101 160.95388(75)# 200# ms β- 161Pm 1/2-#
  1. ^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
  2. ^ Abbreviations:
    EC: Electron capture
    IT: Isomeric transition
  3. ^ Bold for stable isotopes
  4. ^ Theoretically capable of Spontaneous fission
  5. ^ a b c d e f g h Fission product
  6. ^ Used in Samarium-neodymium dating
  7. ^ Theorized to undergo α decay to 139Ce
  8. ^ a b Primordial radionuclide
  9. ^ Theorized to undergo α decay to 141Ce with a half-life over 6×1016 years
  10. ^ Theorized to undergo α decay to 142Ce
  11. ^ Theorized to undergo α decay to 144Ce with a half-life over 3.0×1018 years

Notes[edit]

  • Evaluation of isotopic composition is for most but not all commercial samples.
  • Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
  • Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
  • Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

References[edit]

  1. ^ http://www.nucleonica.net/unc.aspx


Isotopes of praseodymium Isotopes of neodymium Isotopes of promethium
Table of nuclides