Isotopes of niobium

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 are 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).

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

|-id=Niobium-81 | ⁸¹Nb | style="text-align:right" | 41 | style="text-align:right" | 40 | | | | | | |-id=Niobium-82 | ⁸²Nb | style="text-align:right" | 41 | style="text-align:right" | 41 | 81.94438(32) | 51(5)&nbsp;ms | β⁺ | ⁸²Zr | (0+) | |-id=Niobium-82m | style="text-indent:1em" | ^82mNb | colspan="3" style="text-indent:2em" | 1180(1)&nbsp;keV | 93(20)&nbsp;ns | IT | ⁸²Nb | (5+) | |-id=Niobium-83 | ⁸³Nb | style="text-align:right" | 41 | style="text-align:right" | 42 | 82.938133(10) | 3.9(2)&nbsp;s | β⁺ | ⁸³Zr | 9/2+# | |-id=Niobium-84 | ⁸⁴Nb | style="text-align:right" | 41 | style="text-align:right" | 43 | 83.93430571(43) | 9.8(9)&nbsp;s | β⁺ | ⁸⁴Zr | (1+) | |-id=Niobium-84m1 | style="text-indent:1em" | ^84m1Nb | colspan="3" style="text-indent:2em" | 48(1)&nbsp;keV | 176(46)&nbsp;ns | IT | ⁸⁴Nb | (3+) | |-id=Niobium-84m2 | style="text-indent:1em" | ^84m2Nb | colspan="3" style="text-indent:2em" | 337.7(4)&nbsp;keV | 92(5)&nbsp;ns | IT | ⁸⁴Nb | (5−) | |-id=Niobium-85 | ⁸⁵Nb | style="text-align:right" | 41 | style="text-align:right" | 44 | 84.9288458(44) | 20.5(7)&nbsp;s | β⁺ | ⁸⁵Zr | 9/2+# | |-id=Niobium-85m | rowspan=2 style="text-indent:1em" | ^85mNb | rowspan=2 colspan="3" style="text-indent:2em" | 150(80)#&nbsp;keV | rowspan=2|3.3(9)&nbsp;s | IT (?%) | ⁸⁵Nb | rowspan=2|(1/2−) | rowspan=2| |- | β⁺ (?%) | ⁸⁵Zr |-id=Niobium-86 | ⁸⁶Nb | style="text-align:right" | 41 | style="text-align:right" | 45 | 85.9257815(59) | 88(1)&nbsp;s | β⁺ | ⁸⁶Zr | (6+) | |-id=Niobium-86m | style="text-indent:1em" | ^86mNb | colspan="3" style="text-indent:2em" | 150(100)#&nbsp;keV | 20#&nbsp;s | β⁺ | ⁸⁶Zr | (0−,1−,2−) | |-id=Niobium-87 | ⁸⁷Nb | style="text-align:right" | 41 | style="text-align:right" | 46 | 86.9206925(73) | 3.7(1)&nbsp;min | β⁺ | ⁸⁷Zr | (1/2)− | |-id=Niobium-87m | style="text-indent:1em" | ^87mNb | colspan="3" style="text-indent:2em" | 3.9(1)&nbsp;keV | 2.6(1)&nbsp;min | β⁺ | ⁸⁷Zr | (9/2)+ | |-id=Niobium-88 | ⁸⁸Nb | style="text-align:right" | 41 | style="text-align:right" | 47 | 87.918226(62) | 14.50(11)&nbsp;min | β⁺ | ⁸⁸Zr | (8+) | |-id=Niobium-88m | style="text-indent:1em" | ^88mNb | colspan="3" style="text-indent:2em" | 130(120)&nbsp;keV | 7.7(1)&nbsp;min | β⁺ | ⁸⁸Zr | (4−) | |-id=Niobium-89 | ⁸⁹Nb | style="text-align:right" | 41 | style="text-align:right" | 48 | 88.913445(25) | 2.03(7)&nbsp;h | β⁺ | ⁸⁹Zr | (9/2+) | |-id=Niobium-89m | style="text-indent:1em" | ^89mNb | colspan="3" style="text-indent:2em" | 0(30)#&nbsp;keV | 1.10(3)&nbsp;h | β⁺ | ⁸⁹Zr | (1/2)− | |-id=Niobium-90 | ⁹⁰Nb | style="text-align:right" | 41 | style="text-align:right" | 49 | 89.9112592(36) | 14.60(5)&nbsp;h | β⁺ | ⁹⁰Zr | 8+ | |-id=Niobium-90m1 | style="text-indent:1em" | ^90m1Nb | colspan="3" style="text-indent:2em" | 122.370(22)&nbsp;keV | 63(2)&nbsp;μs | IT | ⁹⁰Nb | 6+ | |-id=Niobium-90m2 | style="text-indent:1em" | ^90m2Nb | colspan="3" style="text-indent:2em" | 124.67(25)&nbsp;keV | 18.81(6)&nbsp;s | IT | ⁹⁰Nb | 4- | |-id=Niobium-90m3 | style="text-indent:1em" | ^90m3Nb | colspan="3" style="text-indent:2em" | 171.10(10)&nbsp;keV | <1&nbsp;μs | IT | ⁹⁰Nb | 7+ | |-id=Niobium-90m4 | style="text-indent:1em" | ^90m4Nb | colspan="3" style="text-indent:2em" | 382.01(25)&nbsp;keV | 6.19(8)&nbsp;ms | IT | ^90m1Nb | 1+ | |-id=Niobium-90m5 | style="text-indent:1em" | ^90m5Nb | colspan="3" style="text-indent:2em" | 1880.21(20)&nbsp;keV | 471(6)&nbsp;ns | IT | ⁹⁰Nb | (11−) | |-id=Niobium-91 | rowspan=2|⁹¹Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 50 | rowspan=2|90.9069903(31) | rowspan=2|680(130)&nbsp;y | EC (99.99%) | rowspan=2|⁹¹Zr | rowspan=2|9/2+ | rowspan=2| |- | β⁺ (0.0138%) |-id=Niobium-91m1 | rowspan=3 style="text-indent:1em" | ^91m1Nb | rowspan=3 colspan="3" style="text-indent:2em" | 104.60(5)&nbsp;keV | rowspan=3|60.86(22)&nbsp;d | IT (96.6%) | ⁹¹Nb | rowspan=3|1/2− | rowspan=3| |- | EC (3.4%) | rowspan=2|⁹¹Zr |- | β⁺ (0.0028%) |-id=Niobium-91m2 | style="text-indent:1em" | ^91m2Nb | colspan="3" style="text-indent:2em" | 2034.42(20)&nbsp;keV | 3.76(12)&nbsp;μs | IT | ⁹¹Nb | (17/2−) | |- | ⁹²Nb | style="text-align:right" | 41 | style="text-align:right" | 51 | 91.9071886(19) | 3.47(24)×10⁷&nbsp;y | β⁺ | ⁹²Zr | 7+ | Trace |-id=Niobium-92m1 | style="text-indent:1em" | ^92m1Nb | colspan="3" style="text-indent:2em" | 135.5(4)&nbsp;keV | 10.116(13)&nbsp;d | β⁺ | ⁹²Zr | (2)+ | |-id=Niobium-92m2 | style="text-indent:1em" | ^92m2Nb | colspan="3" style="text-indent:2em" | 225.8(4)&nbsp;keV | 5.9(2)&nbsp;μs | IT | ⁹²Nb | (2)− | |-id=Niobium-92m3 | style="text-indent:1em" | ^92m3Nb | colspan="3" style="text-indent:2em" | 2203.3(4)&nbsp;keV | 167(4)&nbsp;ns | IT | ⁹²Nb | (11−) | |-id=Niobium-93 | ⁹³Nb | style="text-align:right" | 41 | style="text-align:right" | 52 | 92.9063732(16) | colspan=3 align=center|Stable | 9/2+ | 1.0000 |-id=Niobium-93m1 | style="text-indent:1em" | ^93m1Nb | colspan="3" style="text-indent:2em" | 30.760(5)&nbsp;keV | 16.12(12)&nbsp;y | IT | ⁹³Nb | 1/2− | |-id=Niobium-93m2 | style="text-indent:1em" | ^93m2Nb | colspan="3" style="text-indent:2em" | 7460(17)&nbsp;keV | 1.5(5)&nbsp;μs | IT | ⁹³Nb | 33/2−# | |-id=Niobium-94 | ⁹⁴Nb | style="text-align:right" | 41 | style="text-align:right" | 53 | 93.9072790(16) | 2.04(4)×10⁴&nbsp;y | β^− | ⁹⁴Mo | 6+ | Trace |-id=Niobium-94m | rowspan=2 style="text-indent:1em" | ^94mNb | rowspan=2 colspan="3" style="text-indent:2em" | 40.892(12)&nbsp;keV | rowspan=2|6.263(4)&nbsp;min | IT (99.50%) | ⁹⁴Nb | rowspan=2|3+ | rowspan=2| |- | β^− (0.50%) | ⁹⁴Mo |-id=Niobium-95 | ⁹⁵Nb | style="text-align:right" | 41 | style="text-align:right" | 54 | 94.90683111(55) | 34.991(6)&nbsp;d | β^− | ⁹⁵Mo | 9/2+ | |-id=Niobium-95m | rowspan=2 style="text-indent:1em" | ^95mNb | rowspan=2 colspan="3" style="text-indent:2em" | 235.69(2)&nbsp;keV | rowspan=2|3.61(3)&nbsp;d | IT (94.4%) | ⁹⁵Nb | rowspan=2|1/2− | rowspan=2| |- | β^− (5.6%) | ⁹⁵Mo |-id=Niobium-96 | ⁹⁶Nb | style="text-align:right" | 41 | style="text-align:right" | 55 | 95.90810159(16) | 23.35(5)&nbsp;h | β^− | ⁹⁶Mo | 6+ | |-id=Niobium-97 | ⁹⁷Nb | style="text-align:right" | 41 | style="text-align:right" | 56 | 96.9081016(46) | 72.1(7)&nbsp;min | β^− | ⁹⁷Mo | 9/2+ | |-id=Niobium-97m | style="text-indent:1em" | ^97mNb | colspan="3" style="text-indent:2em" | 743.35(3)&nbsp;keV | 58.7(18)&nbsp;s | IT | ⁹⁷Nb | 1/2− | |-id=Niobium-98 | ⁹⁸Nb | style="text-align:right" | 41 | style="text-align:right" | 57 | 97.9103326(54) | 2.86(6)&nbsp;s | β^− | ⁹⁸Mo | 1+ | |-id=Niobium-98m | style="text-indent:1em" | ^98mNb | colspan="3" style="text-indent:2em" | 84(4)&nbsp;keV | 51.1(4)&nbsp;min | β^− | ⁹⁸Mo | (5)+ | |-id=Niobium-99 | ⁹⁹Nb | style="text-align:right" | 41 | style="text-align:right" | 58 | 98.911609(13) | 15.0(2)&nbsp;s | β^− | ⁹⁹Mo | 9/2+ | |-id=Niobium-99m | rowspan=2 style="text-indent:1em" | ^99mNb | rowspan=2 colspan="3" style="text-indent:2em" | 365.27(8)&nbsp;keV | rowspan=2|2.5(2)&nbsp;min | β^− (?%) | ⁹⁹Mo | rowspan=2|1/2− | rowspan=2| |- | IT (?%) | ⁹⁹Nb |-id=Niobium-100 | ¹⁰⁰Nb | style="text-align:right" | 41 | style="text-align:right" | 59 | 99.9143406(86) | 1.5(2)&nbsp;s | β^− | ¹⁰⁰Mo | 1+ | |-id=Niobium-100m1 | style="text-indent:1em" | ^100m1Nb | colspan="3" style="text-indent:2em" | 313(8)&nbsp;keV | 2.99(11)&nbsp;s | β^− | ¹⁰⁰Mo | (5+) | |-id=Niobium-100m2 | style="text-indent:1em" | ^100m2Nb | colspan="3" style="text-indent:2em" | 347(8)&nbsp;keV | 460(60)&nbsp;ns | IT | ¹⁰⁰Nb | (4−,5−) | |-id=Niobium-100m3 | style="text-indent:1em" | ^100m3Nb | colspan="3" style="text-indent:2em" | 734(8)&nbsp;keV | 12.43(26)&nbsp;μs | IT | ¹⁰⁰Nb | (8−) | |-id=Niobium-101 | ¹⁰¹Nb | style="text-align:right" | 41 | style="text-align:right" | 60 | 100.9153065(40) | 7.1(3)&nbsp;s | β^− | ¹⁰¹Mo | 5/2+ | |-id=Niobium-102 | ¹⁰²Nb | style="text-align:right" | 41 | style="text-align:right" | 61 | 101.9180904(27) | 4.3(4)&nbsp;s | β^− | ¹⁰²Mo | (4+) | |-id=Niobium-102m | style="text-indent:1em" | ^102mNb | colspan="3" style="text-indent:2em" | 94(7)&nbsp;keV | 1.31(16)&nbsp;s | β^− | ¹⁰²Mo | (1+) | |-id=Niobium-103 | ¹⁰³Nb | style="text-align:right" | 41 | style="text-align:right" | 62 | 102.9194534(42) | 1.34(7)&nbsp;s | β^− | ¹⁰³Mo | 5/2+ | |-id=Niobium-104 | rowspan=2|¹⁰⁴Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 63 | rowspan=2|103.9229077(19) | rowspan=2|0.98(5)&nbsp;s | β^− (99.95%) | ¹⁰⁴Mo | rowspan=2|(1+) | rowspan=2| |- | β^−, n (0.05%) | ¹⁰³Mo |-id=Niobium-104m | rowspan=2 style="text-indent:1em" | ^104mNb | rowspan=2 colspan="3" style="text-indent:2em" | 9.8(26)&nbsp;keV | rowspan=2|4.9(3)&nbsp;s | β^− (99.94%) | ¹⁰⁴Mo | rowspan=2|(0−,1−) | rowspan=2| |- | β^−, n (0.06%) | ¹⁰³Mo |-id=Niobium-105 | rowspan=2|¹⁰⁵Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 64 | rowspan=2|104.9249426(43) | rowspan=2|2.91(5)&nbsp;s | β^− (98.3%) | ¹⁰⁵Mo | rowspan=2|(5/2+) | rowspan=2| |- | β^−, n (1.7%) | ¹⁰⁴Mo |-id=Niobium-106 | rowspan=2|¹⁰⁶Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 65 | rowspan=2|105.9289285(15) | rowspan=2|900(20)&nbsp;ms | β^− (95.5%) | ¹⁰⁶Mo | rowspan=2|1−# | rowspan=2| |- | β^−, n (4.5%) | ¹⁰⁵Mo |-id=Niobium-106m1 | style="text-indent:1em" | ^106m1Nb | colspan="3" style="text-indent:2em" | 100(50)#&nbsp;keV | 1.20(6)&nbsp;s | β^− | ¹⁰⁶Mo | (4−) | |-id=Niobium-106m2 | style="text-indent:1em" | ^106m2Nb | colspan="3" style="text-indent:2em" | 204.8(5)&nbsp;keV | 820(38)&nbsp;ns | IT | ¹⁰⁶Nb | (3+) | |-id=Niobium-107 | rowspan=2|¹⁰⁷Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 66 | rowspan=2|106.9315897(86) | rowspan=2|286(8)&nbsp;ms | β^− (92.6%) | ¹⁰⁷Mo | rowspan=2|(5/2+) | rowspan=2| |- | β^−, n (7.4%) | ¹⁰⁶Mo |-id=Niobium-108 | rowspan=2|¹⁰⁸Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 67 | rowspan=2|107.9360756(88) | rowspan=2|201(4)&nbsp;ms | β^− (93.7%) | ¹⁰⁸Mo | rowspan=2|(2+) | rowspan=2| |- | β^−, n (6.3%) | ¹⁰⁷Mo |-id=Niobium-108m | style="text-indent:1em" | ^108mNb | colspan="3" style="text-indent:2em" | 166.6(5)&nbsp;keV | 109(2)&nbsp;ns | IT | ¹⁰⁸Nb | 6−# | |-id=Niobium-109 | rowspan=2|¹⁰⁹Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 68 | rowspan=2|108.93914(46) | rowspan=2|106.9(49)&nbsp;ms | β^− (69%) | ¹⁰⁹Mo | rowspan=2|3/2−# | rowspan=2| |- | β^−, n (31%) | ¹⁰⁸Mo |-id=Niobium-109m | style="text-indent:1em" | ^109mNb | colspan="3" style="text-indent:2em" | 312.5(4)&nbsp;keV | 115(8)&nbsp;ns | IT | ¹⁰⁹Nb | 7/2+# | |-id=Niobium-110 | rowspan=2|¹¹⁰Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 69 | rowspan=2|109.94384(90) | rowspan=2|75(1)&nbsp;ms | β^− (60%) | ¹¹⁰Mo | rowspan=2|5+# | rowspan=2| |- | β^−, n (40%) | ¹⁰⁹Mo |-id=Niobium-110m | rowspan=2 style="text-indent:1em" | ^110mNb | rowspan=2 colspan="3" style="text-indent:2em" | 100(50)#&nbsp;keV | rowspan=2|94(9)&nbsp;ms | β^− (60%) | ¹¹⁰Mo | rowspan=2|2+# | rowspan=2| |- | β^−, n (40%) | ¹⁰⁹Mo |-id=Niobium-111 | ¹¹¹Nb | style="text-align:right" | 41 | style="text-align:right" | 70 | 110.94744(32)# | 54(2)&nbsp;ms | β^− | ¹¹¹Mo | 3/2−# | |-id=Niobium-112 | ¹¹²Nb | style="text-align:right" | 41 | style="text-align:right" | 71 | 111.95269(32)# | 38(2)&nbsp;ms | β^− | ¹¹²Mo | 1+# | |-id=Niobium-113 | ¹¹³Nb | style="text-align:right" | 41 | style="text-align:right" | 72 | 112.95683(43)# | 32(4)&nbsp;ms | β^− | ¹¹³Mo | 3/2−# | |-id=Niobium-114 | ¹¹⁴Nb | style="text-align:right" | 41 | style="text-align:right" | 73 | 113.96247(54)# | 17(5)&nbsp;ms | β^− | ¹¹⁴Mo | 2−# | |-id=Niobium-115 | ¹¹⁵Nb | style="text-align:right" | 41 | style="text-align:right" | 74 | 114.96685(54)# | 23(8)&nbsp;ms | β^− | ¹¹⁵Mo | 3/2−# | |-id=Niobium-116 | ¹¹⁶Nb | style="text-align:right" | 41 | style="text-align:right" | 75 | 115.97291(32)# | 12#&nbsp;ms<br />[>550&nbsp;ns] | | | 1−# | |-id=Niobium-117 | ¹¹⁷Nb | style="text-align:right" | 41 | style="text-align:right" | 76 | | | | | |

Niobium-92

Niobium-92 is an extinct radionuclide 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. 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.

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.

See also

Daughter products other than niobium

• Isotopes of molybdenum
• Isotopes of zirconium

References