Isotopes of neodymium
Nuclides with atomic number of 60 but with different mass numbers
Naturally occurring neodymium (60 Nd) is composed of 5 stable isotopes , 142 Nd, 143 Nd, 145 Nd, 146 Nd and 148 Nd, with 142 Nd being the most abundant (27.2% natural abundance ), and 2 long-lived radioisotopes , 144 Nd and 150 Nd. In all, 33 radioisotopes of neodymium have been characterized up to now, with the most stable being naturally occurring isotopes 144 Nd (alpha decay , a half-life (t1/2 ) of 2.29×1015 years) and 150 Nd (double beta decay , t1/2 of 7×1018 years), and for practical purposes they can be considered to be stable as well. All of the remaining radioactive isotopes have half-lives that are less than 12 days, and the majority of these have half-lives that are less than 70 seconds; the most stable artificial isotope is 147 Nd with a half-life of 10.98 days. This element also has 13 known meta states with the most stable being 139m Nd (t1/2 5.5 hours), 135m Nd (t1/2 5.5 minutes) and 133m1 Nd (t1/2 ~70 seconds).
The primary decay modes before the most abundant stable isotope (also the only theoretically stable isotope), 142 Nd, are electron capture and positron decay , and the primary mode after is beta decay . The primary decay products before 142 Nd are praseodymium isotopes and the primary products after are promethium isotopes.
Neodymium isotopes as fission products
Neodymium is one of the more common fission products that results from the splitting of uranium-233 , uranium-235 , plutonium-239 and plutonium-241 . The distribution of resulting neodymium isotopes is distinctly different than those found in crustal rock formation on Earth. One of the methods used to verify that the Oklo Fossil Reactors in Gabon had produced a natural nuclear fission reactor some two billion years before present was to compare the relative abundances of neodymium isotopes found at the reactor site with those found elsewhere on Earth.[4] [5] [6]
List of isotopes
Nuclide[n 1]
Z
N
Isotopic mass (Da ) [n 2] [n 3]
Half-life [n 4] [n 5]
Decay mode [n 6]
Daughter isotope [n 7]
Spin andparity [n 8] [n 5]
Natural abundance (mole fraction)
Excitation energy[n 5]
Normal proportion
Range of variation
124 Nd
60
64
123.95223(64)#
500# ms
0+
125 Nd
60
65
124.94888(43)#
600(150) ms
5/2(+#)
126 Nd
60
66
125.94322(43)#
1# s [>200 ns]
β+
126 Pr
0+
127 Nd
60
67
126.94050(43)#
1.8(4) s
β+
127 Pr
5/2+#
β+ , p (rare)
126 Ce
128 Nd
60
68
127.93539(21)#
5# s
β+
128 Pr
0+
β+ , p (rare)
127 Ce
129 Nd
60
69
128.93319(22)#
4.9(2) s
β+
129 Pr
5/2+#
β+ , p (rare)
128 Ce
130 Nd
60
70
129.92851(3)
21(3) s
β+
130 Pr
0+
131 Nd
60
71
130.92725(3)
33(3) s
β+
131 Pr
(5/2)(+#)
β+ , p (rare)
130 Ce
132 Nd
60
72
131.923321(26)
1.56(10) min
β+
132 Pr
0+
133 Nd
60
73
132.92235(5)
70(10) s
β+
133 Pr
(7/2+)
133m1 Nd
127.97(11) keV
~70 s
β+
133 Pr
(1/2)+
133m2 Nd
176.10(10) keV
~300 ns
(9/2–)
134 Nd
60
74
133.918790(13)
8.5(15) min
β+
134 Pr
0+
134m Nd
2293.1(4) keV
410(30) μs
(8)–
135 Nd
60
75
134.918181(21)
12.4(6) min
β+
135 Pr
9/2(–)
135m Nd
65.0(2) keV
5.5(5) min
β+
135 Pr
(1/2+)
136 Nd
60
76
135.914976(13)
50.65(33) min
β+
136 Pr
0+
137 Nd
60
77
136.914567(12)
38.5(15) min
β+
137 Pr
1/2+
137m Nd
519.43(17) keV
1.60(15) s
IT
137 Nd
(11/2–)
138 Nd
60
78
137.911950(13)
5.04(9) h
β+
138 Pr
0+
138m Nd
3174.9(4) keV
410(50) ns
(10+)
139 Nd
60
79
138.911978(28)
29.7(5) min
β+
139 Pr
3/2+
139m1 Nd
231.15(5) keV
5.50(20) h
β+ (88.2%)
139 Pr
11/2–
IT (11.8%)
139 Nd
139m2 Nd
2570.9+X keV
≥141 ns
140 Nd
60
80
139.90955(3)
3.37(2) d
EC
140 Pr
0+
140m Nd
2221.4(1) keV
600(50) μs
7–
141 Nd
60
81
140.909610(4)
2.49(3) h
β+
141 Pr
3/2+
141m Nd
756.51(5) keV
62.0(8) s
IT (99.95%)
141 Nd
11/2–
β+ (.05%)
141 Pr
142 Nd
60
82
141.9077233(25)
Stable
0+
0.272(5)
0.2680–0.2730
143 Nd[n 9]
60
83
142.9098143(25)
Observationally Stable [n 10]
7/2−
0.122(2)
0.1212–0.1232
144 Nd[n 9] [n 11]
60
84
143.9100873(25)
2.29(16)×1015 y
α
140 Ce
0+
0.238(3)
0.2379–0.2397
145 Nd[n 9]
60
85
144.9125736(25)
Observationally Stable [n 12]
7/2−
0.083(1)
0.0823–0.0835
146 Nd[n 9]
60
86
145.9131169(25)
Observationally Stable [n 13]
0+
0.172(3)
0.1706–0.1735
147 Nd[n 9]
60
87
146.9161004(25)
10.98(1) d
β−
147 Pm
5/2−
148 Nd[n 9]
60
88
147.916893(3)
Observationally Stable [n 14]
0+
0.057(1)
0.0566–0.0578
149 Nd[n 9]
60
89
148.920149(3)
1.728(1) h
β−
149 Pm
5/2−
150 Nd[n 9] [n 11] [n 15]
60
90
149.920891(3)
9.3(7)×1018 y [1]
β− β−
150 Sm
0+
0.056(2)
0.0553–0.0569
151 Nd
60
91
150.923829(3)
12.44(7) min
β−
151 Pm
3/2+
152 Nd
60
92
151.924682(26)
11.4(2) min
β−
152 Pm
0+
153 Nd
60
93
152.927698(29)
31.6(10) s
β−
153 Pm
(3/2)−
154 Nd
60
94
153.92948(12)
25.9(2) s
β−
154 Pm
0+
154m1 Nd
480(150)# keV
1.3(5) μs
154m2 Nd
1349(10) keV
>1 μs
(5−)
155 Nd
60
95
154.93293(16)#
8.9(2) s
β−
155 Pm
3/2−#
156 Nd
60
96
155.93502(22)
5.49(7) s
β−
156 Pm
0+
156m Nd
1432(5) keV
135 ns
5−
157 Nd
60
97
156.93903(21)#
1.17(4) s[9]
β−
157 Pm
5/2−#
158 Nd
60
98
157.94160(43)#
700# ms [>300 ns]
β−
158 Pm
0+
159 Nd
60
99
158.94609(54)#
500# ms
β−
159 Pm
7/2+#
160 Nd
60
100
159.94909(64)#
300# ms
β−
160 Pm
0+
161 Nd
60
101
160.95388(75)#
200# ms
β−
161 Pm
1/2−#
This table header & footer:
^ m Nd – Excited nuclear isomer .
^ ( ) – Uncertainty (1σ ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^ Bold half-life – nearly stable, half-life longer than age of universe .
^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^
Modes of decay:
^ Bold symbol as daughter – Daughter product is stable.
^ ( ) spin value – Indicates spin with weak assignment arguments.
^ a b c d e f g h Fission product
^ Believed to undergo α decay to 139 Ce with a half-life over 2.8× 1019 years[1] [7] [8]
^ a b Primordial radionuclide
^ Believed to undergo α decay to 141 Ce with a half-life of over 6.1× 1019 years[1] [7] [8]
^ Believed to undergo β− β− decay to 146 Sm or α decay to 142 Ce with a half-life of over 3.3× 1021 years[1] [7] [8]
^ Believed to undergo β− β− decay to 148 Sm or α decay to 144 Ce with a half-life of over 1.2× 1019 years[1] [7] [8]
^ Predicted to be capable of undergoing triple beta decay and quadruple beta decay with very long partial half-lives
References
^ a b c d e f g Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF) . Chinese Physics C . 45 (3): 030001. doi :10.1088/1674-1137/abddae .
^ "Standard Atomic Weights: Neodymium" . CIAAW . 2005.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)" . Pure and Applied Chemistry . doi :10.1515/pac-2019-0603 . ISSN 1365-3075 .
^ Hemond, C.; Menet, C.; Menager, M.T. (1991). "U and Nd Isotopes from the New Oklo Reactor 10 (GABON): Evidence for Radioelements Migration" . MRS Proceedings . 257 . doi :10.1557/PROC-257-489 .
^ "Oklo's Natural Nuclear Reactors" . 24 October 2020.
^ "The Implications of the Oklo Phenomenon on the Constancy of Radiometric Decay Rates" .
^ a b c d Sokur, N.V.; Belli, P.; Bernabei, R.; Boiko, R.S.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Danevich, F.A.; Incicchitti, A.; Kasperovych, D.V.; Kobychev, V.V.; Laubenstein, M.; Leoncini, A.; Merlo, V.; Polischuk, O.G.; Tretyak, V.I. (11 July 2023). Alpha decay of naturally occurring neodymium isotopes . XII International Conference on New Frontiers in Physics.
^ a b c d Belli, P.; Bernabei, R.; Danevich, F. A.; Incicchitti, A.; Tretyak, V. I. (2019). "Experimental searches for rare alpha and beta decays". European Physical Journal A . 55 (140): 4–6. arXiv :1908.11458 . Bibcode :2019EPJA...55..140B . doi :10.1140/epja/i2019-12823-2 . S2CID 201664098 .
^ Hartley, D. J.; Kondev, F. G.; Carpenter, M. P.; Clark, J. A.; Copp, P.; Kay, B.; Lauritsen, T.; Savard, G.; Seweryniak, D.; Wilson, G. L.; Wu, J. (2023-08-14). "First β− -decay spectroscopy study of 157 Nd". Physical Review C . 108 (2). American Physical Society (APS): 024307. Bibcode :2023PhRvC.108b4307H . doi :10.1103/physrevc.108.024307 . ISSN 2469-9985 . S2CID 260913513 .
Isotope masses from:
Isotopic compositions and standard atomic masses from:
"News & Notices: Standard Atomic Weights Revised" . International Union of Pure and Applied Chemistry . 19 October 2005.
Half-life, spin, and isomer data selected from the following sources.
Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties" , Nuclear Physics A , 729 : 3–128, Bibcode :2003NuPhA.729....3A , doi :10.1016/j.nuclphysa.2003.11.001
National Nuclear Data Center . "NuDat 2.x database" . Brookhaven National Laboratory .
Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida : CRC Press . ISBN 978-0-8493-0485-9 .
Group
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Period
Hydrogen and alkali metals
Alkaline earth metals
Pnictogens
Chalcogens
Halogens
Noble gases
①
1
2
②
3
4
5
6
7
8
9
10
③
11
12
13
14
15
16
17
18
④
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
⑤
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
⑥
55
56
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
⑦
87
88
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
⑧
119
120
57
58
59
60
61
62
63
64
65
66
67
68
69
70
89
90
91
92
93
94
95
96
97
98
99
100
101
102