Isotopes of lutetium

Naturally occurring lutetium (Lu) is composed of 1 stable isotope ¹⁷⁵Lu (97.41% natural abundance) and one long-lived radioisotope, ¹⁷⁶Lu with a half-life of 3.78 × 10¹⁰ years (2.59% natural abundance). Thirty-four radioisotopes have been characterized, with the most stable, besides ¹⁷⁶Lu, being ¹⁷⁴Lu with a half-life of 3.31 years, and ¹⁷³Lu with a half-life of 1.37 years. All of the remaining radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than half an hour. This element also has 18 meta states, with the most stable being ^177mLu (t_1/2 160.4 days), ^174mLu (t_1/2 142 days) and ^178mLu (t_1/2 23.1 minutes).

The isotopes of lutetium range in atomic weight from 149.973 (¹⁵⁰Lu) to 183.961 (¹⁸⁴Lu). The primary decay mode before the most abundant stable isotope, ¹⁷⁵Lu, is electron capture (with some alpha and positron emission), and the primary mode after is beta emission. The primary decay products before ¹⁷⁵Lu are isotopes of ytterbium and the primary products after are isotopes of hafnium.

Relative atomic mass: 174.9668(1).^[1]

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life[n 1]	decay mode(s)[2][n 2]	daughter isotope(s)[n 3]	nuclear spin	representative isotopic composition (mole fraction)
	excitation energy
^150Lu	71	79	149.97323(54)#	43(5) ms	p (80%)	^149Yb	(2+)
					β^+ (20%)	^150Yb
^150mLu	34(15) keV			80(60) µs [30(+95−15) µs]	p	^149Yb	(1,2)
^151Lu	71	80	149.97323(54)#	80.6(5) ms	p (63.4%)	^150Yb	(11/2−)
					β^+ (36.6%)	^151Yb
^151mLu	77(5) keV			16(1) µs	p	^150Yb	(3/2+)
^152Lu	71	81	151.96412(21)#	650(70) ms	β^+ (85%)	^152Yb	(5−,6−)
					β^+, p (15%)	^151Tm
^153Lu	71	82	152.95877(22)	0.9(2) s	α (70%)	^149Tm	11/2−
					β^+ (30%)	^153Yb
^153m1Lu	80(5) keV			1# s	IT	^153Yb	1/2+
^153m2Lu	2502.5(4) keV			>0.1 µs	IT	^153Yb	23/2−
^153m3Lu	2632.9(5) keV			15(3) µs	IT	^153m2Yb	27/2−
^154Lu	71	83	153.95752(22)#	1# s	β^+	^154Yb	(2−)
^154m1Lu	58(13) keV			1.12(8) s			(9+)
^154m2Lu	>2562 keV			35(3) µs			(17+)
^155Lu	71	84	154.954316(22)	68.6(16) ms	α (76%)	^151Tm	(11/2−)
					β^+ (24%)	^155Yb
^155m1Lu	20(6) keV			138(8) ms	α (88%)	^151Tm	(1/2+)
					β^+ (12%)	^155Yb
^155m2Lu	1781.0(20) keV			2.70(3) ms			(25/2−)
^156Lu	71	85	155.95303(8)	494(12) ms	α (95%)	^152Tm	(2)−
					β^+ (5%)	^156Yb
^156mLu	220(80)# keV			198(2) ms	α (94%)	^152Tm	(9)+
					β^+ (6%)	^156Yb
^157Lu	71	86	156.950098(20)	6.8(18) s	β^+	^157Yb	(1/2+,3/2+)
					α	^153Tm
^157mLu	21.0(20) keV			4.79(12) s	β^+ (94%)	^157Yb	(11/2−)
					α (6%)	^153Tm
^158Lu	71	87	157.949313(16)	10.6(3) s	β^+ (99.09%)	^158Yb	2−
					α (.91%)	^154Tm
^159Lu	71	88	158.94663(4)	12.1(10) s	β^+ (99.96%)	^159Yb	1/2+#
					α (.04%)	^155Tm
^159mLu	100(80)# keV			10# s			11/2−#
^160Lu	71	89	159.94603(6)	36.1(3) s	β^+	^160Yb	2−#
					α (10^−4%)	^156Tm
^160mLu	0(100)# keV			40(1) s
^161Lu	71	90	160.94357(3)	77(2) s	β^+	^161Yb	1/2+
^161mLu	166(18) keV			7.3(4) ms	IT	^161Lu	(9/2−)
^162Lu	71	91	161.94328(8)	1.37(2) min	β^+	^162Yb	(1−)
^162m1Lu	120(200)# keV			1.5 min	β^+	^162Yb	4−#
					IT (rare)	^162Lu
^162m2Lu	300(200)# keV			1.9 min
^163Lu	71	92	162.94118(3)	3.97(13) min	β^+	^163Yb	1/2(+)
^164Lu	71	93	163.94134(3)	3.14(3) min	β^+	^164Yb	1(−)
^165Lu	71	94	164.939407(28)	10.74(10) min	β^+	^165Yb	1/2+
^166Lu	71	95	165.93986(3)	2.65(10) min	β^+	^166Yb	(6−)
^166m1Lu	34.37(5) keV			1.41(10) min	EC (58%)	^166Yb	3(−)
					IT (42%)	^166Lu
^166m2Lu	42.9(5) keV			2.12(10) min			0(−)
^167Lu	71	96	166.93827(3)	51.5(10) min	β^+	^167Yb	7/2+
^167mLu	0(30)# keV			>1 min			1/2(−#)
^168Lu	71	97	167.93874(5)	5.5(1) min	β^+	^168Yb	(6−)
^168mLu	180(110) keV			6.7(4) min	β^+ (95%)	^168Yb	3+
					IT (5%)	^168Lu
^169Lu	71	98	168.937651(6)	34.06(5) h	β^+	^169Yb	7/2+
^169mLu	29.0(5) keV			160(10) s	IT	^169Lu	1/2−
^170Lu	71	99	169.938475(18)	2.012(20) d	β^+	^170Yb	0+
^170mLu	92.91(9) keV			670(100) ms	IT	^170Lu	(4)−
^171Lu	71	100	170.9379131(30)	8.24(3) d	β^+	^171Yb	7/2+
^171mLu	71.13(8) keV			79(2) s	IT	^171Lu	1/2−
^172Lu	71	101	171.939086(3)	6.70(3) d	β^+	^172Yb	4−
^172m1Lu	41.86(4) keV			3.7(5) min	IT	^172Lu	1−
^172m2Lu	65.79(4) keV			0.332(20) µs			(1)+
^172m3Lu	109.41(10) keV			440(12) µs			(1)+
^172m4Lu	213.57(17) keV			150 ns			(6−)
^173Lu	71	102	172.9389306(26)	1.37(1) y	EC	^173Yb	7/2+
^173mLu	123.672(13) keV			74.2(10) µs			5/2−
^174Lu	71	103	173.9403375(26)	3.31(5) y	β^+	^174Yb	(1)−
^174m1Lu	170.83(5) keV			142(2) d	IT (99.38%)	^174Lu	6−
					EC (.62%)	^174Yb
^174m2Lu	240.818(4) keV			395(15) ns			(3+)
^174m3Lu	365.183(6) keV			145(3) ns			(4−)
^175Lu	71	104	174.9407718(23)	Observationally Stable[n 4]			7/2+	0.9741(2)
^175m1Lu	1392.2(6) keV			984(30) µs			(19/2+)
^175m2Lu	353.48(13) keV			1.49(7) µs			5/2−
^176Lu[n 5][n 6]	71	105	175.9426863(23)	38.5(7)×10^9 y	β^−	^176Hf	7−	0.0259(2)
^176mLu	122.855(6) keV			3.664(19) h	β^− (99.9%)	^176Hf	1−
					EC (.095%)	^176Yb
^177Lu	71	106	176.9437581(23)	6.6475(20) d	β^−	^177Hf	7/2+
^177m1Lu	150.3967(10) keV			130(3) ns			9/2−
^177m2Lu	569.7068(16) keV			155(7) µs			1/2+
^177m3Lu	970.1750(24) keV			160.44(6) d	β^− (78.3%)	^177Hf	23/2−
					IT (21.7%)	^177Lu
^177m4Lu	3900(10) keV			7(2) min [6(+3−2) min]			39/2−
^178Lu	71	107	177.945955(3)	28.4(2) min	β^−	^178Hf	1(+)
^178mLu	123.8(26) keV			23.1(3) min	β^−	^178Hf	9(−)
^179Lu	71	108	178.947327(6)	4.59(6) h	β^−	^179Hf	7/2(+)
^179mLu	592.4(4) keV			3.1(9) ms	IT	^179Lu	1/2(+)
^180Lu	71	109	179.94988(8)	5.7(1) min	β^−	^180Hf	5+
^180m1Lu	13.9(3) keV			~1 s	IT	^180Lu	3−
^180m2Lu	624.0(5) keV			>=1 ms			(9−)
^181Lu	71	110	180.95197(32)#	3.5(3) min	β^−	^181Hf	(7/2+)
^182Lu	71	111	181.95504(21)#	2.0(2) min	β^−	^182Hf	(0,1,2)
^183Lu	71	112	182.95757(32)#	58(4) s	β^−	^183Hf	(7/2+)
^184Lu	71	113	183.96091(43)#	20(3) s	β^−	^184Hf	(3+)

1. Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
2. Abbreviations:
   EC: Electron capture
   IT: Isomeric transition
3. Bold for stable isotopes
4. Believed to undergo α decay to ¹⁷¹Tm
5. primordial radionuclide
6. Used in Lutetium-Hafnium dating

Notes

• 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

1. Table of Standard Atomic Weights 2013 – CIAAW
2. "Universal Nuclide Chart". nucleonica. (registration required (help)).

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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:
  • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • M. E. Wieser (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. See editing notes on this article's talk page.
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005. Check date values in: |access-date= (help)
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.