Isotopes of niobium

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Naturally occurring niobium (41Nb) is composed of one stable isotope (93Nb). The most stable radioisotope is 92Nb with a half-life of 34.7 million years, followed by 94Nb at a half-life of 20,400 years and 91Nb at 680 years. Other radioisotopes that have been synthesized range from 82Nb to 110Nb; these have half-lives that are less than two hours, except 95Nb (34.991 days), 96Nb (23.35 hours) and 90Nb (14.60 hours).

Quick facts Main isotopes, Decay ...
Isotopes of niobium (41Nb)
Main isotopes[1] Decay
Isotope abun­dance half-life (t1/2) mode pro­duct
91Nb synth 680 y β+ 91Zr
91mNb synth 60.86 d IT 91Nb
β+ 91Zr
92Nb trace 3.47×107 y β+ 92Zr
93Nb 100% stable
93mNb synth 16.1 y IT 93Nb
94Nb trace 2.04×104 y β− 94Mo
95Nb synth 34.991 d β− 95Mo
Standard atomic weight Ar°(Nb)
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The most stable of the meta states is 93mNb with excitation energy 31 keV and a 16.1 year half-life; this is produced in the decay of 93Zr. The primary decay mode before stable 93Nb is electron capture to zirconium isotopes and the primary mode after is beta emission, with delayed neutron emission starting at 104Nb, leading to molybdenum isotopes.

Only 95Nb, along with 97Nb (72 minutes) and heavier isotopes (seconds) are fission products in significant quantity, as the other isotopes are shadowed by stable or very long-lived (93) isotopes of the preceding element zirconium from the usual mode of production through beta decay of neutron-rich fission fragments. 95Nb is the decay product of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35-day half-life alone.

List of isotopes


More information Nuclide, Z ...
Nuclide
[n 1]		 Z N Isotopic mass (Da)[4]
[n 2][n 3]		 Discovery
year[5][6]		 Half-life[1]
[n 4]		 Decay
mode[1]
[n 5]		 Daughter
isotope
[n 6][n 7]		 Spin and
parity[1]
[n 8][n 4]		 Isotopic
abundance
Excitation energy[n 4]
82Nb 41 41 81.94438(32) 1992 51(5) ms β+ 82Zr (0+)
82mNb 1180(1) keV 2008 93(20) ns IT 82Nb (5+)
83Nb 41 42 82.938133(10)[7] 1988 3.9(2) s β+ 83Zr 9/2+#
84Nb 41 43 83.93430571(43) 1977 9.8(9) s β+ 84Zr (1+)
84m1Nb 48(1) keV 2009 176(46) ns IT 84Nb (3+)
84m2Nb 337.7(4) keV (2000)[n 9] 92(5) ns IT 84Nb (5−)
85Nb 41 44 84.9288458(44) 1988 20.5(7) s β+ 85Zr 9/2+#
85mNb 150(80)# keV 2005 3.3(9) s IT (?%) 85Nb (1/2−)
β+ (?%) 85Zr
86Nb 41 45 85.9257815(59) 1974 88(1) s β+ 86Zr (6+)
86mNb[n 10] 150(100)# keV (1994)[n 11] 20# s β+ 86Zr (0−,1−,2−)
87Nb 41 46 86.9206925(73) 1971 3.7(1) min β+ 87Zr (1/2)−
87mNb 3.9(1) keV 1972 2.6(1) min β+ 87Zr (9/2)+
88Nb 41 47 87.918226(62) 1964 14.50(11) min β+ 88Zr (8+)
88mNb[n 10] 130(120) keV 1971 7.7(1) min β+ 88Zr (4−)
89Nb 41 48 88.913445(25) 1954 2.03(7) h β+ 89Zr (9/2+)
89mNb[n 10] 0(30)# keV 1954 1.10(3) h β+ 89Zr (1/2)−
90Nb 41 49 89.9112592(36) 1951 14.60(5) h β+ 90Zr 8+
90m1Nb 122.370(22) keV 1967 63(2) μs IT 90Nb 6+
90m2Nb 124.67(25) keV 1955 18.81(6) s IT 90Nb 4-
90m3Nb 171.10(10) keV (1981)[n 12] <1 μs IT 90Nb 7+
90m4Nb 382.01(25) keV 1955 6.19(8) ms IT 90m1Nb 1+
90m5Nb 1880.21(20) keV 1981 471(6) ns IT 90Nb (11−)
91Nb 41 50 90.9069903(31) 1951 680(130) y EC (99.99%) 91Zr 9/2+
β+ (0.0138%)
91m1Nb 104.60(5) keV 1965 60.86(22) d IT (96.6%) 91Nb 1/2−
EC (3.4%) 91Zr
β+ (0.0028%)
91m2Nb 2034.42(20) keV 1974 3.76(12) μs IT 91Nb (17/2−)
92Nb 41 51 91.9071886(19) 1938 3.47(24)×107 y β+ 92Zr 7+ Trace
92m1Nb 135.5(4) keV 1959 10.116(13) d β+ 92Zr (2)+
92m2Nb 225.8(4) keV 1958 5.9(2) μs IT 92Nb (2)−
92m3Nb 2203.3(4) keV 1977 167(4) ns IT 92Nb (11−)
93Nb 41 52 92.9063732(16) 1932 Stable 9/2+ 1.0000
93m1Nb 30.760(5) keV 1965 16.12(12) y IT 93Nb 1/2−
93m2Nb 7460(17) keV 2007 1.5(5) μs IT 93Nb 33/2−#
94Nb 41 53 93.9072790(16) 1938 2.04(4)×104 y β− 94Mo 6+ Trace
94mNb 40.892(12) keV 1950 6.263(4) min IT (99.50%) 94Nb 3+
β− (0.50%) 94Mo
95Nb[n 13] 41 54 94.90683111(55) 1946 34.991(6) d β− 95Mo 9/2+
95mNb[n 13] 235.69(2) keV 1951 3.61(3) d IT (94.4%) 95Nb 1/2−
β− (5.6%) 95Mo
96Nb 41 55 95.90810159(16) 1949 23.35(5) h β− 96Mo 6+ Trace[n 14]
97Nb 41 56 96.9081016(46) 1951 72.1(7) min β− 97Mo 9/2+
97mNb 743.35(3) keV 1950 58.7(18) s IT 97Nb 1/2−
98Nb 41 57 97.9103326(54) 1960 2.86(6) s β− 98Mo 1+
98mNb 84(4) keV 1967 51.1(4) min β− 98Mo (5)+
99Nb 41 58 98.911609(13) 1950 15.0(2) s β− 99Mo 9/2+
99mNb 365.27(8) keV 1963 2.5(2) min β− (?%) 99Mo 1/2−
IT (?%) 99Nb
100Nb 41 59 99.9143406(86) 1967 1.5(2) s β− 100Mo 1+
100m1Nb 313(8) keV 1976 2.99(11) s β− 100Mo (5+)
100m2Nb 347(8) keV 1970 460(60) ns IT 100Nb (4−,5−)
100m3Nb 734(8) keV 1999 12.43(26) μs IT 100Nb (8−)
101Nb 41 60 100.9153065(40) 1970 7.1(3) s β− 101Mo 5/2+
102Nb 41 61 101.9180904(27) 1972 4.3(4) s β− 102Mo (4+)
102mNb 94(7) keV 1976 1.31(16) s β− 102Mo (1+)
103Nb 41 62 102.9194534(42) 1971 1.34(7) s β− 103Mo 5/2+
104Nb 41 63 103.9229077(19) 1971 0.98(5) s β− (99.95%) 104Mo (1+)
β−, n (0.05%) 103Mo
104mNb[n 10] 9.8(26) keV 1976 4.9(3) s β− (99.94%) 104Mo (0−,1−)
β−, n (0.06%) 103Mo
105Nb 41 64 104.9249426(43) 1984 2.91(5) s β− (98.3%) 105Mo (5/2+)
β−, n (1.7%) 104Mo
106Nb 41 65 105.9289285(15) 1976 900(20) ms β− (95.5%) 106Mo 1−#
β−, n (4.5%) 105Mo
106m1Nb 100(50)# keV (2020)[n 15] 1.20(6) s β− 106Mo (4−)
106m2Nb 204.8(5) keV 1999 820(38) ns IT 106Nb (3+)
107Nb 41 66 106.9315897(86) 1992 286(8) ms β− (92.6%) 107Mo (5/2+)
β−, n (7.4%) 106Mo
108Nb 41 67 107.9360756(88) 1994 201(4) ms β− (93.7%) 108Mo (2+)
β−, n (6.3%) 107Mo
108mNb 166.6(5) keV 2012 109(2) ns IT 108Nb 6−#
109Nb 41 68 108.93914(46) 1994 106.9(49) ms β− (69%) 109Mo 3/2−#
β−, n (31%) 108Mo
109mNb 312.5(4) keV 2011 115(8) ns IT 109Nb 7/2+#
110Nb 41 69 109.94384(90) 1994 75(1) ms β− (60%) 110Mo 5+#
β−, n (40%) 109Mo
110mNb[n 10] 100(50)# keV 2020 94(9) ms β− (60%) 110Mo 2+#
β−, n (40%) 109Mo
111Nb 41 70 110.94744(32)# 1997 54(2) ms β− 111Mo 3/2−#
112Nb 41 71 111.95269(32)# 1997 38(2) ms β− 112Mo 1+#
113Nb 41 72 112.95683(43)# 1997 32(4) ms β− 113Mo 3/2−#
113mNb 135 keV 2022 700(400) ns IT 113Nb
114Nb 41 73 113.96247(54)# 2010 17(5) ms β− 114Mo 2−#
115Nb 41 74 114.96685(54)# 2010 23(8) ms β− 115Mo 3/2−#
116Nb 41 75 115.97291(32)# 2018 12# ms
[>550 ns]		 1−#
117Nb[8] 41 76 2021
This table header & footer:
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  1. [1]
    mNb – Excited nuclear isomer.
  2. [2]
    ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. [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. [4]
    # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. [5]
    Modes of decay:
    EC:Electron capture
    IT:Isomeric transition
    n:Neutron emission
    p:Proton emission
  6. [6]
    Bold italics symbol as daughter – Daughter product is nearly stable.
  7. [7]
    Bold symbol as daughter – Daughter product is stable.
  8. [8]
    ( ) spin value – Indicates spin with weak assignment arguments.
  9. [9]
    Half-life shorter than 100 ns, not included in the discovery database
  10. [10]
    Order of ground state and isomer is uncertain.
  11. [11]
    Only assumed, no property measured
  12. [12]
    Half-life not measured, state only assumed
  13. [13]
    Fission product
  14. [14]
    Intermediate decay product of 96Zr
  15. [15]
    Not separately measured from the ground state, the isomeric is assumed to be different

Niobium-92

Niobium-92 is an extinct radionuclide[9] with a half-life of 34.7 million years, decaying predominantly via β+ decay. Its abundance relative to the stable 93Nb in the early Solar System, estimated at 1.7×10−5, has been measured to investigate the origin of p-nuclei.[9][10] A higher initial abundance of 92Nb has been estimated for material in the outer protosolar disk (sampled from the meteorite NWA 6704), suggesting that this nuclide was predominantly formed via the gamma process (photodisintegration) in a nearby core-collapse supernova.[11]

Niobium-92, along with niobium-94, has been detected in refined samples of terrestrial niobium and may originate from bombardment by cosmic ray muons in Earth's crust.[12]

See also

Daughter products other than niobium

References

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