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Isotopes of dysprosium



Naturally occurring Dysprosium (Dy) is composed of 7 stable isotopes, 156-Dy, 158-Dy, 160-Dy, 161-Dy, 162-Dy, 163-Dy and 164-Dy, with 164-Dy being the most abundant (28.18% natural abundance). 28 radioisotopes have been characterized, with the most stable being 154-Dy with a half-life of 3.0E+6 years, 159-Dy with a half-life of 144.4 days, and 166-Dy with a half-life of 81.6 hours. All of the remaining radioactive isotopes have half-lifes that are less than 10 hours, and the majority of these have half lifes that are less than 30 seconds. This element also has 5 meta states, with the most stable being 165m-Dy (t½ 1.257 minutes), 147m-Dy (t½ 55.7 seconds) and 145m-Dy (t½ 13.6 seconds).

The primary decay mode before the most abundant stable isotope, 164-Dy, is electron capture, and the primary mode after is beta minus decay. The primary decay products before 164-Dy are terbium isotopes, and the primary products after are holmium isotopes.
Standard atomic mass: 162.500(1) u

Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
138Dy 66 72 137.96249(64)# 200# ms 0+
139Dy 66 73 138.95954(54)# 600(200) ms 7/2+#
140Dy 66 74 139.95401(54)# 700# ms 0+
140mDy 2166.1(5) keV 7.0(5) µs (8-)
141Dy 66 75 140.95135(32)# 0.9(2) s (9/2-)
142Dy 66 76 141.94637(39)# 2.3(3) s 0+
143Dy 66 77 142.94383(21)# 5.6(10) s (1/2+)
143mDy 310.7(6) keV 3.0(3) s (11/2-)
144Dy 66 78 143.93925(3) 9.1(4) s 0+
145Dy 66 79 144.93743(5) 9.5(10) s (1/2+)
145mDy 118.2(2) keV 14.1(7) s (11/2-)
146Dy 66 80 145.932845(29) 33.2(7) s 0+
146mDy 2935.7(6) keV 150(20) ms (10+)#
147Dy 66 81 146.931092(21) 40(10) s 1/2+
147m1Dy 750.5(4) keV 55(1) s 11/2-
147m2Dy 3407.2(8) keV 0.40(1) µs (27/2-)
148Dy 66 82 147.927150(11) 3.3(2) min 0+
149Dy 66 83 148.927305(9) 4.20(14) min 7/2(-)
149mDy 2661.1(4) keV 490(15) ms (27/2-)
150Dy 66 84 149.925585(5) 7.17(5) min 0+
151Dy 66 85 150.926185(4) 17.9(3) min 7/2(-)
152Dy 66 86 151.924718(6) 2.38(2) h 0+
153Dy 66 87 152.925765(5) 6.4(1) h 7/2(-)
154Dy 66 88 153.924424(8) 3.0(15)E+6 a 0+
155Dy 66 89 154.925754(13) 9.9(2) h 3/2-
155mDy 234.33(3) keV 6(1) µs 11/2-
156Dy 66 90 155.924283(7) STABLE [>1E+18 a] 0+ 0.00056(3)
157Dy 66 91 156.925466(7) 8.14(4) h 3/2-
157m1Dy 161.99(3) keV 1.3(2) µs 9/2+
157m2Dy 199.38(7) keV 21.6(16) ms 11/2-
158Dy 66 92 157.924409(4) STABLE 0+ 0.00095(3)
159Dy 66 93 158.9257392(29) 144.4(2) d 3/2-
159mDy 352.77(14) keV 122(3) µs 11/2-
160Dy 66 94 159.9251975(27) STABLE 0+ 0.02329(18)
161Dy 66 95 160.9269334(27) STABLE 5/2+ 0.18889(42)
162Dy 66 96 161.9267984(27) STABLE 0+ 0.25475(36)
163Dy 66 97 162.9287312(27) STABLE 5/2- 0.24896(42)
164Dy 66 98 163.9291748(27) STABLE 0+ 0.28260(54)
165Dy 66 99 164.9317033(27) 2.334(1) h 7/2+
165mDy 108.160(3) keV 1.257(6) min 1/2-
166Dy 66 100 165.9328067(28) 81.6(1) h 0+
167Dy 66 101 166.93566(6) 6.20(8) min (1/2-)
168Dy 66 102 167.93713(15) 8.7(3) min 0+
169Dy 66 103 168.94031(32) 39(8) s (5/2-)
170Dy 66 104 169.94239(21)# 30# s 0+
171Dy 66 105 170.94620(32)# 6# s 7/2-#
172Dy 66 106 171.94876(43)# 3# s 0+
173Dy 66 107 172.95300(54)# 2# s 9/2+#

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

  • Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
  • Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
  • Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
    • Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
    • National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
    • David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.


Isotopes of terbium Isotopes of dysprosium Isotopes of holmium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_dysprosium". A list of authors is available in Wikipedia.
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