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Isotopes of zirconium

Naturally occurring zirconium (40Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (Zr), a primordial nuclide that decays via double beta decay with an observed half-life of 2.0×10 years; it can also undergo single beta decay, which is not yet observed, but the theoretically predicted value of t1/2 is 2.4×10 years. The second most stable radioisotope is Zr, which has a half-life of 1.53 million years. Twenty-seven other radioisotopes have been observed. All have half-lives less than a day except for Zr (64.02 days), Zr (83.4 days), and Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than Zr, and the primary mode for heavier isotopes is beta decay.

List of isotopes



|- | Zr | style="text-align:right" | 40 | style="text-align:right" | 38 | 77.95523(54)# | 50# ms
[>170 ns] | | | 0+ | | |- | rowspan=2|Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 39 | rowspan=2|78.94916(43)# | rowspan=2|56(30) ms | β, p | Sr | rowspan=2|5/2+# | rowspan=2| | rowspan=2| |- | β | Y |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 40 | 79.9404(16) | 4.6(6) s | β | Y | 0+ | | |- | rowspan=2|Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 41 | rowspan=2|80.93721(18) | rowspan=2|5.5(4) s | β (>99.9%) | Y | rowspan=2|(3/2−)# | rowspan=2| | rowspan=2| |- | β, p (<.1%) | Sr |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 42 | 81.93109(24)# | 32(5) s | β | Y | 0+ | | |- | rowspan=2|Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 43 | rowspan=2|82.92865(10) | rowspan=2|41.6(24) s | β (>99.9%) | Y | rowspan=2|(1/2−)# | rowspan=2| | rowspan=2| |- | β, p (<.1%) | Sr |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 44 | 83.92325(21)# | 25.9(7) min | β | Y | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 45 | 84.92147(11) | 7.86(4) min | β | Y | 7/2+ | | |- | rowspan=2 style="text-indent:1em" | Zr | rowspan=2 colspan="3" style="text-indent:2em" | 292.2(3) keV | rowspan=2|10.9(3) s | IT (92%) | Zr | rowspan=2|(1/2−) | rowspan=2| | rowspan=2| |- | β (8%) | Y |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 46 | 85.91647(3) | 16.5(1) h | β | Y | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 47 | 86.914816(9) | 1.68(1) h | β | Y | (9/2)+ | | |- | style="text-indent:1em" | Zr | colspan="3" style="text-indent:2em" | 335.84(19) keV | 14.0(2) s | IT | Zr | (1/2)− | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 48 | 87.910227(11) | 83.4(3) d | EC | Y | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 49 | 88.908890(4) | 78.41(12) h | β | Y | 9/2+ | | |- | rowspan=2 style="text-indent:1em" | Zr | rowspan=2 colspan="3" style="text-indent:2em" | 587.82(10) keV | rowspan=2|4.161(17) min | IT (93.77%) | Zr | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | β (6.23%) | Y |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 50 | 89.9047044(25) | colspan=3 align=center|Stable | 0+ | 0.5145(40) | |- | style="text-indent:1em" | Zr | colspan="3" style="text-indent:2em" | 2319.000(10) keV | 809.2(20) ms | IT | Zr | 5- | | |- | style="text-indent:1em" | Zr | colspan="3" style="text-indent:2em" | 3589.419(16) keV | 131(4) ns | | | 8+ | | |- | Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 53 | rowspan=2 | 92.9064760(25) | rowspan=2 | 1.53(10)×10 y | β (73%) | Nb | rowspan=2 | 5/2+ | rowspan=2 | | rowspan=2 | |- | β (27%) | Nb |- | Zr | 0+ | 0.1738(28) | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 56 | 95.9082734(30) | 20(4)×10 y | ββ | Mo | 0+ | 0.0280(9) | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 57 | 96.9109531(30) | 16.744(11) h | β | Nb | 1/2+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 58 | 97.912735(21) | 30.7(4) s | β | Nb | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 59 | 98.916512(22) | 2.1(1) s | β | Nb | 1/2+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 60 | 99.91776(4) | 7.1(4) s | β | Nb | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 61 | 100.92114(3) | 2.3(1) s | β | Nb | 3/2+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 62 | 101.92298(5) | 2.9(2) s | β | Nb | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 63 | 102.92660(12) | 1.3(1) s | β | Nb | (5/2−) | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 64 | 103.92878(43)# | 1.2(3) s | β | Nb | 0+ | | |- | rowspan=2|Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 65 | rowspan=2|104.93305(43)# | rowspan=2|0.6(1) s | β (>99.9%) | Nb | rowspan=2| | rowspan=2| | rowspan=2| |- | β, n (<.1%) | Nb |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 66 | 105.93591(54)# | 200# ms
[>300 ns] | β | Nb | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 67 | 106.94075(32)# | 150# ms
[>300 ns] | β | Nb | | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 68 | 107.94396(64)# | 80# ms
[>300 ns] | β | Nb | 0+ | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 69 | 108.94924(54)# | 60# ms
[>300 ns] | | | | | |- | Zr | style="text-align:right" | 40 | style="text-align:right" | 70 | 109.95287(86)# | 30# ms
[>300 ns] | | | 0+ | |

Zirconium-88

Zr is a radioisotope of zirconium with a half-life of 83.4 days. In January 2019, this isotope was discovered to have a neutron capture cross section of approximately 861,000 barns; this is several orders of magnitude greater than predicted, and greater than that of any other nuclide except xenon-135.

Zirconium-89

Zr is a radioisotope of zirconium with a half-life of 78.41 hours. It is produced by proton irradiation of natural yttrium-89. Its most prominent gamma photon has an energy of 909 keV.

Zirconium-89 is employed in specialized diagnostic applications using positron emission tomography imaging, for example, with zirconium-89 labeled antibodies (immuno-PET). For a decay table, see

Zirconium-93





Zr is a radioisotope of zirconium with a half-life of 1.53 million years, decaying through emission of a low-energy beta particle. 73% of decays populate an excited state of niobium-93, which decays with a halflife of 14 years and a low-energy gamma ray to the stable ground state of Nb, while the remaining 27% of decays directly populate the ground state. It is one of only 7 long-lived fission products. The low specific activity and low energy of its radiations limit the radioactive hazards of this isotope.

Nuclear fission produces it at a fission yield of 6.3% (thermal neutron fission of U), on a par with the other most abundant fission products. Nuclear reactors usually contain large amounts of zirconium as fuel rod cladding (see zircaloy), and neutron irradiation of Zr also produces some Zr, though this is limited by Zr's low neutron capture cross section of 0.22 barns.

Zr also has a low neutron capture cross section of 0.7 barns. Most fission zirconium consists of other isotopes; the other isotope with a significant neutron absorption cross section is Zr with a cross section of 1.24 barns. Zr is a less attractive candidate for disposal by nuclear transmutation than are Tc and I. Mobility in soil is relatively low, so that geological disposal may be an adequate solution.