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Isotopes of neodymium



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, 31 radioisotopes of Neodymium have been characterized up to now, with the most stable being naturally occurring isotopes 144Nd (alpha decay, a half-life (T½) of 2.29×1015 years) and 150Nd (double beta decay, T½ 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 (T½ 5.5 hours), 135mNd (T½ 5.5 minutes) and 133m1Nd (T½ ~70 seconds).

Additional recommended knowledge

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

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life 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] 0+
127Nd 60 67 126.94050(43)# 1.8(4) s 5/2+#
128Nd 60 68 127.93539(21)# 5# s 0+
129Nd 60 69 128.93319(22)# 4.9(2) s 5/2+#
130Nd 60 70 129.92851(3) 21(3) s 0+
131Nd 60 71 130.92725(3) 33(3) s (5/2)(+#)
132Nd 60 72 131.923321(26) 1.56(10) min 0+
133Nd 60 73 132.92235(5) 70(10) s (7/2+)
133m1Nd 127.97(11) keV ~70 s (1/2)+
133m2Nd 176.10(10) keV ~300 ns (9/2-)
134Nd 60 74 133.918790(13) 8.5(15) min 0+
134mNd 2293.1(4) keV 410(30) µs (8)-
135Nd 60 75 134.918181(21) 12.4(6) min 9/2(-)
135mNd 65.0(2) keV 5.5(5) min (1/2+)
136Nd 60 76 135.914976(13) 50.65(33) min 0+
137Nd 60 77 136.914567(12) 38.5(15) min 1/2+
137mNd 519.43(17) keV 1.60(15) s (11/2-)
138Nd 60 78 137.911950(13) 5.04(9) h 0+
138mNd 3174.9(4) keV 410(50) ns (10+)
139Nd 60 79 138.911978(28) 29.7(5) min 3/2+
139m1Nd 231.15(5) keV 5.50(20) h 11/2-
139m2Nd 2570.9+X keV >=141 ns
140Nd 60 80 139.90955(3) 3.37(2) d 0+
140mNd 2221.4(1) keV 600(50) µs 7-
141Nd 60 81 140.909610(4) 2.49(3) h 3/2+
141mNd 756.51(5) keV 62.0(8) s 11/2-
142Nd 60 82 141.9077233(25) STABLE 0+ 0.272(5) 0.2680-0.2730
143Nd 60 83 142.9098143(25) STABLE 7/2- 0.122(2) 0.1212-0.1232
144Nd 60 84 143.9100873(25) 2.29(16)E+15 a 0+ 0.238(3) 0.2379-0.2397
145Nd 60 85 144.9125736(25) STABLE 7/2- 0.083(1) 0.0823-0.0835
146Nd 60 86 145.9131169(25) STABLE 0+ 0.172(3) 0.1706-0.1735
147Nd 60 87 146.9161004(25) 10.98(1) d 5/2-
148Nd 60 88 147.916893(3) STABLE [>3.0E+18 a] 0+ 0.057(1) 0.0566-0.0578
149Nd 60 89 148.920149(3) 1.728(1) h 5/2-
150Nd 60 90 149.920891(3) 6.7(7)E+18 a 0+ 0.056(2) 0.0553-0.0569
151Nd 60 91 150.923829(3) 12.44(7) min 3/2+
152Nd 60 92 151.924682(26) 11.4(2) min 0+
153Nd 60 93 152.927698(29) 31.6(10) s (3/2)-
154Nd 60 94 153.92948(12) 25.9(2) s 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 3/2-#
156Nd 60 96 155.93502(22) 5.49(7) s 0+
156mNd 1432(5) keV 135 ns 5-
157Nd 60 97 156.93903(21)# 2# s [>300 ns] 5/2-#
158Nd 60 98 157.94160(43)# 700# ms [>300 ns] 0+
159Nd 60 99 158.94609(54)# 500# ms 7/2+#
160Nd 60 100 159.94909(64)# 300# ms 0+
161Nd 60 101 160.95388(75)# 200# ms 1/2-#

Notes

  • Evaluated 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

  • Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
  • Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
  • Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
    • Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
    • National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
    • David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.


Isotopes of praseodymium Isotopes of neodymium Isotopes of promethium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_neodymium". A list of authors is available in Wikipedia.
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