Naturally occurring

neodymium Neodymium is a chemical element with the symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes i ...

(₆₀Nd) is composed of 5 stable

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass numbers ...

s, ¹⁴²Nd, ¹⁴³Nd, ¹⁴⁵Nd, ¹⁴⁶Nd and ¹⁴⁸Nd, with ¹⁴²Nd being the most abundant (27.2%

natural abundance In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomi ...

), and 2 long-lived

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s, 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 Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a different atomic nucleus, with a mass number that is reduced by four and an ato ...

, a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...

(t_1/2) of 2.29×10¹⁵ years) and ¹⁵⁰Nd (

double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa, inside an atomic nucleus. As in single beta decay, this process allows the atom to move clos ...

, t_1/2 of 7×10¹⁸ years). All of the remaining

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

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 ¹⁴⁷Nd with a half-life of 10.98 days. This element also has 13 known

meta state A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...

s with the most stable being ^139mNd (t_1/2 5.5 hours), ^135mNd (t_1/2 5.5 minutes) and ^133m1Nd (t_1/2 ~70 seconds). The primary

decay mode Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

s before the most abundant stable isotope, ¹⁴²Nd, are

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Th ...

and

positron decay Positron emission, beta plus decay, or β+ decay is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (). Positron emis ...

, and the primary mode after is

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For e ...

. The primary

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps (de ...

s before ¹⁴²Nd are element

praseodymium Praseodymium is a chemical element with the symbol Pr and the atomic number 59. It is the third member of the lanthanide series and is considered to be one of the rare-earth metals. It is a soft, silvery, malleable and ductile metal, valued for i ...

isotopes and the primary products after are element

promethium Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in Earth's crust at any given time. Promethium is one of on ...

isotopes.

Neodymium isotopes as fission products

Neodymium is one of the more common

fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release ...

s that results from the splitting of

uranium-233 Uranium-233 (233U or U-233) is a fissile isotope of uranium that is bred from thorium-232 as part of the thorium fuel cycle. Uranium-233 was investigated for use in nuclear weapons and as a reactor fuel. It has been used successfully in exper ...

uranium-235 Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists ...

plutonium-239 Plutonium-239 (239Pu or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main ...

and

plutonium-241 Plutonium-241 (241Pu or Pu-241) is an isotope of plutonium formed when plutonium-240 captures a neutron. Like some other plutonium isotopes (especially 239Pu), 241Pu is fissile, with a neutron absorption cross section about one-third greater than ...

. 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 Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

had produced a

natural nuclear fission reactor A natural nuclear fission reactor is a uranium deposit where self-sustaining nuclear chain reactions occur. The conditions under which a natural nuclear reactor could exist had been predicted in 1956 by Japanese American chemist Paul Kuroda. T ...

some two billion years before present was to compare the neodymium isotopes found in the formation with those found elsewhere on Earth.

List of isotopes

, - , ¹²⁴Nd , style="text-align:right" , 60 , style="text-align:right" , 64 , 123.95223(64)# , 500# ms , , , 0+ , , , - , ¹²⁵Nd , style="text-align:right" , 60 , style="text-align:right" , 65 , 124.94888(43)# , 600(150) ms , , , 5/2(+#) , , , - , ¹²⁶Nd , style="text-align:right" , 60 , style="text-align:right" , 66 , 125.94322(43)# , 1# s 200 ns, β⁺ , ¹²⁶Pr , 0+ , , , - , rowspan=2, ¹²⁷Nd , rowspan=2 style="text-align:right" , 60 , rowspan=2 style="text-align:right" , 67 , rowspan=2, 126.94050(43)# , rowspan=2, 1.8(4) s , β⁺ , ¹²⁷Pr , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , β⁺, p (rare) , ¹²⁶Ce , - , rowspan=2, ¹²⁸Nd , rowspan=2 style="text-align:right" , 60 , rowspan=2 style="text-align:right" , 68 , rowspan=2, 127.93539(21)# , rowspan=2, 5# s , β⁺ , ¹²⁸Pr , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺, p (rare) , ¹²⁷Ce , - , rowspan=2, ¹²⁹Nd , rowspan=2 style="text-align:right" , 60 , rowspan=2 style="text-align:right" , 69 , rowspan=2, 128.93319(22)# , rowspan=2, 4.9(2) s , β⁺ , ¹²⁹Pr , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , β⁺, p (rare) , ¹²⁸Ce , - , ¹³⁰Nd , style="text-align:right" , 60 , style="text-align:right" , 70 , 129.92851(3) , 21(3) s , β⁺ , ¹³⁰Pr , 0+ , , , - , rowspan=2, ¹³¹Nd , rowspan=2 style="text-align:right" , 60 , rowspan=2 style="text-align:right" , 71 , rowspan=2, 130.92725(3) , rowspan=2, 33(3) s , β⁺ , ¹³¹Pr , rowspan=2, (5/2)(+#) , rowspan=2, , rowspan=2, , - , β⁺, p (rare) , ¹³⁰Ce , - , ¹³²Nd , style="text-align:right" , 60 , style="text-align:right" , 72 , 131.923321(26) , 1.56(10) min , β⁺ , ¹³²Pr , 0+ , , , - , ¹³³Nd , style="text-align:right" , 60 , style="text-align:right" , 73 , 132.92235(5) , 70(10) s , β⁺ , ¹³³Pr , (7/2+) , , , - , style="text-indent:1em" , ^133m1Nd , colspan="3" style="text-indent:2em" , 127.97(11) keV , ~70 s , β⁺ , ¹³³Pr , (1/2)+ , , , - , style="text-indent:1em" , ^133m2Nd , colspan="3" style="text-indent:2em" , 176.10(10) keV , ~300 ns , , , (9/2–) , , , - , ¹³⁴Nd , style="text-align:right" , 60 , style="text-align:right" , 74 , 133.918790(13) , 8.5(15) min , β⁺ , ¹³⁴Pr , 0+ , , , - , style="text-indent:1em" , ^134mNd , colspan="3" style="text-indent:2em" , 2293.1(4) keV , 410(30) µs , , , (8)– , , , - , ¹³⁵Nd , style="text-align:right" , 60 , style="text-align:right" , 75 , 134.918181(21) , 12.4(6) min , β⁺ , ¹³⁵Pr , 9/2(–) , , , - , style="text-indent:1em" , ^135mNd , colspan="3" style="text-indent:2em" , 65.0(2) keV , 5.5(5) min , β⁺ , ¹³⁵Pr , (1/2+) , , , - , ¹³⁶Nd , style="text-align:right" , 60 , style="text-align:right" , 76 , 135.914976(13) , 50.65(33) min , β⁺ , ¹³⁶Pr , 0+ , , , - , ¹³⁷Nd , style="text-align:right" , 60 , style="text-align:right" , 77 , 136.914567(12) , 38.5(15) min , β⁺ , ¹³⁷Pr , 1/2+ , , , - , style="text-indent:1em" , ^137mNd , colspan="3" style="text-indent:2em" , 519.43(17) keV , 1.60(15) s , IT , ¹³⁷Nd , (11/2–) , , , - , ¹³⁸Nd , style="text-align:right" , 60 , style="text-align:right" , 78 , 137.911950(13) , 5.04(9) h , β⁺ , ¹³⁸Pr , 0+ , , , - , style="text-indent:1em" , ^138mNd , colspan="3" style="text-indent:2em" , 3174.9(4) keV , 410(50) ns , , , (10+) , , , - , ¹³⁹Nd , style="text-align:right" , 60 , style="text-align:right" , 79 , 138.911978(28) , 29.7(5) min , β⁺ , ¹³⁹Pr , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^139m1Nd , rowspan=2 colspan="3" style="text-indent:2em" , 231.15(5) keV , rowspan=2, 5.50(20) h , β⁺ (88.2%) , ¹³⁹Pr , rowspan=2, 11/2– , rowspan=2, , rowspan=2, , - , IT (11.8%) , ¹³⁹Nd , - , style="text-indent:1em" , ^139m2Nd , colspan="3" style="text-indent:2em" , 2570.9+X keV , ≥141 ns , , , , , , - , ¹⁴⁰Nd , style="text-align:right" , 60 , style="text-align:right" , 80 , 139.90955(3) , 3.37(2) d , EC , ¹⁴⁰Pr , 0+ , , , - , style="text-indent:1em" , ^140mNd , colspan="3" style="text-indent:2em" , 2221.4(1) keV , 600(50) µs , , , 7– , , , - , ¹⁴¹Nd , style="text-align:right" , 60 , style="text-align:right" , 81 , 140.909610(4) , 2.49(3) h , β⁺ , ¹⁴¹Pr , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^141mNd , rowspan=2 colspan="3" style="text-indent:2em" , 756.51(5) keV , rowspan=2, 62.0(8) s , IT (99.95%) , ¹⁴¹Nd , rowspan=2, 11/2– , rowspan=2, , rowspan=2, , - , β⁺ (.05%) , ¹⁴¹Pr , - , ¹⁴²Nd , style="text-align:right" , 60 , style="text-align:right" , 82 , 141.9077233(25) , colspan=3 align=center, StableTheoretically capable of

Spontaneous fission Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements. The nuclear binding energy of the elements reaches its maximum at an atomic mass number of about 56 (e.g., iron-56); spontaneous breakdow ...

, 0+ , 0.272(5) , 0.2680–0.2730 , - , ¹⁴³NdFission product , style="text-align:right" , 60 , style="text-align:right" , 83 , 142.9098143(25) , colspan=3 align=center,

Observationally Stable Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes. Th ...

, 7/2− , 0.122(2) , 0.1212–0.1232 , - , ¹⁴⁴Nd Primordial

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

, style="text-align:right" , 60 , style="text-align:right" , 84 , 143.9100873(25) , 2.29(16)×10¹⁵ y , α , ¹⁴⁰Ce , 0+ , 0.238(3) , 0.2379–0.2397 , - , ¹⁴⁵Nd , style="text-align:right" , 60 , style="text-align:right" , 85 , 144.9125736(25) , colspan=3 align=center, Observationally Stable , 7/2− , 0.083(1) , 0.0823–0.0835 , - , ¹⁴⁶Nd , style="text-align:right" , 60 , style="text-align:right" , 86 , 145.9131169(25) , colspan=3 align=center, Observationally Stable , 0+ , 0.172(3) , 0.1706–0.1735 , - , ¹⁴⁷Nd , style="text-align:right" , 60 , style="text-align:right" , 87 , 146.9161004(25) , 10.98(1) d , β⁻ , ¹⁴⁷Pm , 5/2− , , , - , ¹⁴⁸Nd , style="text-align:right" , 60 , style="text-align:right" , 88 , 147.916893(3) , colspan=3 align=center, Observationally Stable , 0+ , 0.057(1) , 0.0566–0.0578 , - , ¹⁴⁹Nd , style="text-align:right" , 60 , style="text-align:right" , 89 , 148.920149(3) , 1.728(1) h , β⁻ , ¹⁴⁹Pm , 5/2− , , , - , ¹⁵⁰Nd , style="text-align:right" , 60 , style="text-align:right" , 90 , 149.920891(3) , 6.7(7)×10¹⁸ y , β⁻β⁻ , ¹⁵⁰Sm , 0+ , 0.056(2) , 0.0553–0.0569 , - , ¹⁵¹Nd , style="text-align:right" , 60 , style="text-align:right" , 91 , 150.923829(3) , 12.44(7) min , β⁻ , ¹⁵¹Pm , 3/2+ , , , - , ¹⁵²Nd , style="text-align:right" , 60 , style="text-align:right" , 92 , 151.924682(26) , 11.4(2) min , β⁻ , ¹⁵²Pm , 0+ , , , - , ¹⁵³Nd , style="text-align:right" , 60 , style="text-align:right" , 93 , 152.927698(29) , 31.6(10) s , β⁻ , ¹⁵³Pm , (3/2)− , , , - , ¹⁵⁴Nd , style="text-align:right" , 60 , style="text-align:right" , 94 , 153.92948(12) , 25.9(2) s , β⁻ , ¹⁵⁴Pm , 0+ , , , - , style="text-indent:1em" , ^154m1Nd , colspan="3" style="text-indent:2em" , 480(150)# keV , 1.3(5) µs , , , , , , - , style="text-indent:1em" , ^154m2Nd , colspan="3" style="text-indent:2em" , 1349(10) keV , >1 µs , , , (5−) , , , - , ¹⁵⁵Nd , style="text-align:right" , 60 , style="text-align:right" , 95 , 154.93293(16)# , 8.9(2) s , β⁻ , ¹⁵⁵Pm , 3/2−# , , , - , ¹⁵⁶Nd , style="text-align:right" , 60 , style="text-align:right" , 96 , 155.93502(22) , 5.49(7) s , β⁻ , ¹⁵⁶Pm , 0+ , , , - , style="text-indent:1em" , ^156mNd , colspan="3" style="text-indent:2em" , 1432(5) keV , 135 ns , , , 5− , , , - , ¹⁵⁷Nd , style="text-align:right" , 60 , style="text-align:right" , 97 , 156.93903(21)# , 2# s 300 ns, β⁻ , ¹⁵⁷Pm , 5/2−# , , , - , ¹⁵⁸Nd , style="text-align:right" , 60 , style="text-align:right" , 98 , 157.94160(43)# , 700# ms 300 ns, β⁻ , ¹⁵⁸Pm , 0+ , , , - , ¹⁵⁹Nd , style="text-align:right" , 60 , style="text-align:right" , 99 , 158.94609(54)# , 500# ms , β⁻ , ¹⁵⁹Pm , 7/2+# , , , - , ¹⁶⁰Nd , style="text-align:right" , 60 , style="text-align:right" , 100 , 159.94909(64)# , 300# ms , β⁻ , ¹⁶⁰Pm , 0+ , , , - , ¹⁶¹Nd , style="text-align:right" , 60 , style="text-align:right" , 101 , 160.95388(75)# , 200# ms , β⁻ , ¹⁶¹Pm , 1/2−# , ,

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Neodymium

Neodymium Neodymium is a chemical element with the symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes i ...