Isotopes of neodymium

Naturally occurring neodymium (₆₀Nd) is composed of 5 stable isotopes, ¹⁴²Nd, ¹⁴³Nd, ¹⁴⁵Nd, ¹⁴⁶Nd and ¹⁴⁸Nd, with ¹⁴²Nd being the most abundant (27.2% natural abundance), and 2 long-lived 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 (t_1/2) of 2.29×10¹⁵ years) and ¹⁵⁰Nd (double beta decay, t_1/2 of 7×10¹⁸ years). 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 ¹⁴⁷Nd with a half-life of 10.98 days. This element also has 13 known meta states 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).

Main isotopes of neodymium (₆₀Nd)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^142Nd 27.2% stable ^143Nd 12.2% stable ^144Nd 23.8% 2.29×10^15 y α ^140Ce ^145Nd 8.3% stable ^146Nd 17.2% stable ^148Nd 5.8% stable ^150Nd 5.6% 6.7×10^18 y β^−β^− ^150Sm
Standard atomic weight Ar, standard(Nd)	144.242(3)[1]

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

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 and parity [n 8][n 5]	Natural abundance (mole fraction)
	Excitation energy[n 5]							Normal proportion	Range of variation
^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			0+	0.272(5)	0.2680–0.2730
^143Nd[n 9]	60	83	142.9098143(25)	Stable			7/2−	0.122(2)	0.1212–0.1232
^144Nd[n 9][n 10]	60	84	143.9100873(25)	2.29(16)×10^15 y	α	^140Ce	0+	0.238(3)	0.2379–0.2397
^145Nd[n 9]	60	85	144.9125736(25)	Stable			7/2−	0.083(1)	0.0823–0.0835
^146Nd[n 9]	60	86	145.9131169(25)	Observationally Stable[n 11]			0+	0.172(3)	0.1706–0.1735
^147Nd[n 9]	60	87	146.9161004(25)	10.98(1) d	β^−	^147Pm	5/2−
^148Nd[n 9]	60	88	147.916893(3)	Observationally Stable[n 12]			0+	0.057(1)	0.0566–0.0578
^149Nd[n 9]	60	89	148.920149(3)	1.728(1) h	β^−	^149Pm	5/2−
^150Nd[n 9][n 10]	60	90	149.920891(3)	6.7(7)×10^18 y	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. ^mNd – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. Bold half-life – nearly stable, half-life longer than age of universe.
5. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
6. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   p:	Proton emission

7. Bold symbol as daughter – Daughter product is stable.
8. ( ) spin value – Indicates spin with weak assignment arguments.
9. Fission product
10. Primordial radionuclide
11. Theorized to undergo β⁻β⁻ decay to ¹⁴⁶Sm or α decay to ¹⁴²Ce
12. Theorized to undergo β⁻β⁻ decay to ¹⁴⁸Sm or α decay to ¹⁴⁴Ce with a half-life over 3.0×10¹⁸ years

References

1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

• Isotope masses from:
  • 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
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• 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.