Isotopes of copper

Copper (Cu) has two stable isotopes, ⁶³Cu and ⁶⁵Cu, along with 27 radioisotopes. The most stable of these is ⁶⁷Cu with a half-life of 61.83 hours. The least stable is ⁵⁴Cu with a half-life of approximately 75 ns. Most have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β⁺ decay, while isotopes with atomic masses above 65 tend to undergo β⁻ decay. ⁶⁴Cu decays by both β⁺ and β⁻.

⁶⁸Cu, ⁶⁹Cu, ⁷¹Cu, ⁷²Cu, and ⁷⁶Cu each have one metastable isomer. ⁷⁰Cu has two isomers, making a total of 7 distinct isomers. The most stable of these is ^68mCu with a half-life of 3.75 minutes. The least stable is ^69mCu with a half-life of 360 ns.

Relative atomic mass: 63.546(3).

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
52Cu	29	23	51.99718(28)#		p	51Ni	(3+)#
53Cu	29	24	52.98555(28)#	<300 ns	p	52Ni	(3/2−)#
54Cu	29	25	53.97671(23)#	<75 ns	p	53Ni	(3+)#
55Cu	29	26	54.96605(32)#	40# ms [>200 ns]	β+	55Ni	3/2−#
					p	54Ni
56Cu	29	27	55.95856(15)#	93(3) ms	β+	56Ni	(4+)
57Cu	29	28	56.949211(17)	196.3(7) ms	β+	57Ni	3/2−
58Cu	29	29	57.9445385(17)	3.204(7) s	β+	58Ni	1+
59Cu	29	30	58.9394980(8)	81.5(5) s	β+	59Ni	3/2−
60Cu	29	31	59.9373650(18)	23.7(4) min	β+	60Ni	2+
61Cu	29	32	60.9334578(11)	3.333(5) h	β+	61Ni	3/2−
62Cu	29	33	61.932584(4)	9.673(8) min	β+	62Ni	1+
63Cu	29	34	62.9295975(6)	Stable			3/2−	0.6915(15)	0.68983–0.69338
64Cu	29	35	63.9297642(6)	12.700(2) h	β+ (61%)	64Ni	1+
					β− (39%)	64Zn
65Cu	29	36	64.9277895(7)	Stable			3/2−	0.3085(15)	0.30662–0.31017
66Cu	29	37	65.9288688(7)	5.120(14) min	β−	66Zn	1+
67Cu	29	38	66.9277303(13)	61.83(12) h	β−	67Zn	3/2−
68Cu	29	39	67.9296109(17)	31.1(15) s	β−	68Zn	1+
68mCu	721.6(7) keV			3.75(5) min	IT (84%)	68Cu	(6-)
					β− (16%)	68Zn
69Cu	29	40	68.9294293(15)	2.85(15) min	β−	69Zn	3/2−
69mCu	2741.8(10) keV			360(30) ns			(13/2+)
70Cu	29	41	69.9323923(17)	44.5(2) s	β−	70Zn	(6-)
70m1Cu	101.1(3) keV			33(2) s	β−	70Zn	(3-)
70m2Cu	242.6(5) keV			6.6(2) s			1+
71Cu	29	42	70.9326768(16)	19.4(14) s	β−	71Zn	(3/2−)
71mCu	2756(10) keV			271(13) ns			(19/2−)
72Cu	29	43	71.9358203(15)	6.6(1) s	β−	72Zn	(1+)
72mCu	270(3) keV			1.76(3) µs			(4-)
73Cu	29	44	72.936675(4)	4.2(3) s	β− (>99.9%)	73Zn	(3/2−)
					β−, n (<.1%)	72Zn
74Cu	29	45	73.939875(7)	1.594(10) s	β−	74Zn	(1+,3+)
75Cu	29	46	74.94190(105)	1.224(3) s	β− (96.5%)	75Zn	(3/2−)#
					β−, n (3.5%)	74Zn
76Cu	29	47	75.945275(7)	641(6) ms	β− (97%)	76Zn	(3,5)
					β−, n (3%)	75Zn
76mCu	0(200)# keV			1.27(30) s	β−	76Zn	(1,3)
77Cu	29	48	76.94785(43)#	469(8) ms	β−	77Zn	3/2−#
78Cu	29	49	77.95196(43)#	342(11) ms	β−	78Zn
79Cu	29	50	78.95456(54)#	188(25) ms	β−, n (55%)	78Zn	3/2−#
					β− (45%)	79Zn
80Cu	29	51	79.96087(64)#	100# ms [>300 ns]	β−	80Zn

Notes

• The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
• 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.
• Nuclide masses are given by IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants (SUNAMCO).
• Isotope abundances are given by IUPAC Commission on Isotopic Abundances and Atomic Weights.

Medical Applications

Copper offers a relatively large number of radioisotopes that are potentially suitable for use in nuclear medicine.

There is a growing interest in the use of ⁶⁴Cu, ⁶²Cu, ⁶¹Cu, and ⁶⁰Cu for diagnostic purposes and ⁶⁷Cu and ⁶⁴Cu for targeted radiotherapy. For example, ⁶⁴Cu has a longer half-life and is thus ideal for diagnostic PET imaging of biological molecules.

References

• Isotope masses from:
• Isotopic compositions and standard atomic masses from:
• Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
• Application of Copper radioisotopes in Medicine (Review Paper):

Isotopes of nickel	Isotopes of copper	Isotopes of zinc
Table of nuclides