Isotopes of zirconium
Encyclopedia
Naturally occurring zirconium
(Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (96Zr), a primordial nuclide
that decays via double beta decay
with an observed half-life
of 2.0×1019 years; it can also undergo single beta decay
which is not yet observed, but the theoretically predicted value of T½ is 2.4×1020 years. The second most stable radioisotope is 93Zr 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 95Zr (64.02 days), 88Zr (63.4 days), and 89Zr (78.41 hours). The primary decay mode is electron capture
for isotopes lighter than 92Zr, and the primary mode for heavier isotopes is beta decay
.
Zirconium is the heaviest element that can be formed from symmetric fusion, from either 45Sc, or 46Ca producing 90Zr (after two beta-plus decays from 90Mo) and 92Zr respectively. All heavier elements are formed either through asymmetric fusion or during the collapse of supernovae. As most of these are energy-absorbing processes, most nuclides of elements heavier than zirconium are theoretically unstable to spontaneous fission, although in many cases, the half-life for this is too long to have been observed. See list of nuclides for a tabulation.
Standard atomic mass: 91.224(2) u.
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 the Zirconium 89 decay Table
with a half-life
of 1.53 million years, decaying with a low-energy beta particle
to Niobium
-93m, which decays with a halflife of 14 years and a low-energy gamma ray
to ordinary 93Nb. It is one of only 7 long-lived fission product
s. 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 6.2956%, 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 92Zr also produces some 93Zr, though this is limited by 92Zr's low neutron capture
cross section
of 0.22 barns.
93Zr also has a low neutron capture
cross section of 2.70 barns. Most fission zirconium consists of other isotopes; the other isotope with a significant neutron absorption cross section is 91Zr with a cross section of 1.24 barns. 93Zr is a less attractive candidate for disposal by nuclear transmutation
than are Tc-99 and I-129
. Mobility in soil is relatively low, so that geological disposal
may be an adequate solution.
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
(Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (96Zr), a primordial nuclide
Primordial nuclide
In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known...
that decays via double beta decay
Double beta decay
Double beta decay is a radioactive decay process where a nucleus releases two beta rays as a single process.In double-beta decay, two neutrons in the nucleus are converted to protons, and two electrons and two electron antineutrinos are emitted...
with an observed half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 2.0×1019 years; it can also undergo single beta decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
which is not yet observed, but the theoretically predicted value of T½ is 2.4×1020 years. The second most stable radioisotope is 93Zr which has a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 1.53 million years. Twenty-seven other radioisotopes have been observed. All have half-lives less than a day except for 95Zr (64.02 days), 88Zr (63.4 days), and 89Zr (78.41 hours). The primary decay mode is electron capture
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...
for isotopes lighter than 92Zr, and the primary mode for heavier isotopes is beta decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
.
Zirconium is the heaviest element that can be formed from symmetric fusion, from either 45Sc, or 46Ca producing 90Zr (after two beta-plus decays from 90Mo) and 92Zr respectively. All heavier elements are formed either through asymmetric fusion or during the collapse of supernovae. As most of these are energy-absorbing processes, most nuclides of elements heavier than zirconium are theoretically unstable to spontaneous fission, although in many cases, the half-life for this is too long to have been observed. See list of nuclides for a tabulation.
Standard atomic mass: 91.224(2) u.
Zirconium-89
89Zr is a radioisotope of zirconiumZirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
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 the Zirconium 89 decay Table
Zirconium-93
93Zr is a radioisotope of zirconiumZirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 1.53 million years, decaying with a low-energy beta particle
Beta particle
Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay...
to Niobium
Niobium
Niobium or columbium , is a chemical element with the symbol Nb and atomic number 41. It's a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite...
-93m, which decays with a halflife of 14 years and a low-energy gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
to ordinary 93Nb. It is one of only 7 long-lived fission product
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...
s. The low specific activity and low energy of its radiations limit the radioactive hazards of this isotope.
Nuclear fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
produces it at a fission yield of 6.2956%, on a par with the other most abundant fission products. Nuclear reactors usually contain large amounts of zirconium as fuel rod cladding (see Zircaloy
Zircaloy
Zirconium alloys are solid solutions of zirconium or other metals, a common subgroup having the trade mark Zircaloy. Zirconium has very low absorption cross-section of thermal neutrons, high hardness, ductility and corrosion resistance...
), and neutron irradiation of 92Zr also produces some 93Zr, though this is limited by 92Zr's low neutron capture
Neutron capture
Neutron capture is a kind of nuclear reaction in which an atomic nucleus collides with one or more neutrons and they merge to form a heavier nucleus. Since neutrons have no electric charge they can enter a nucleus more easily than positively charged protons, which are repelled...
cross section
Neutron cross-section
In nuclear and particle physics, the concept of a neutron cross section is used to express the likelihood of interaction between an incident neutron and a target nucleus. In conjunction with the neutron flux, it enables the calculation of the reaction rate, for example to derive the thermal power...
of 0.22 barns.
93Zr also has a low neutron capture
Neutron capture
Neutron capture is a kind of nuclear reaction in which an atomic nucleus collides with one or more neutrons and they merge to form a heavier nucleus. Since neutrons have no electric charge they can enter a nucleus more easily than positively charged protons, which are repelled...
cross section of 2.70 barns. Most fission zirconium consists of other isotopes; the other isotope with a significant neutron absorption cross section is 91Zr with a cross section of 1.24 barns. 93Zr is a less attractive candidate for disposal by nuclear transmutation
Nuclear transmutation
Nuclear transmutation is the conversion of one chemical element or isotope into another. In other words, atoms of one element can be changed into atoms of other element by 'transmutation'...
than are Tc-99 and I-129
Iodine-129
Iodine-129 is long-lived radioisotope of iodine which occurs naturally, but also is of special interest in the monitoring and effects of man-made nuclear fission decay products, where it serves as both tracer and potential radiological contaminant....
. Mobility in soil is relatively low, so that geological disposal
Deep geological repository
A deep geological repository is a nuclear waste repository excavated deep within a stable geologic environment...
may be an adequate solution.
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-lifeBold for isotopes with half-lives longer than the age of the universe (nearly stable) | decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 78Zr | 40 | 38 | 77.95523(54)# | 50# ms [>170 ns] |
0+ | ||||
| 79Zr | 40 | 39 | 78.94916(43)# | 56(30) ms | β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... , p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
78Sr | 5/2+# | ||
| β+ | 79Y | ||||||||
| 80Zr | 40 | 40 | 79.9404(16) | 4.6(6) s | β+ | 80Y | 0+ | ||
| 81Zr | 40 | 41 | 80.93721(18) | 5.5(4) s | β+ (>99.9%) | 81Y | (3/2-)# | ||
| β+, p (<.1%) | 80Sr | ||||||||
| 82Zr | 40 | 42 | 81.93109(24)# | 32(5) s | β+ | 82Y | 0+ | ||
| 83Zr | 40 | 43 | 82.92865(10) | 41.6(24) s | β+ (>99.9%) | 83Y | (1/2-)# | ||
| β+, p (<.1%) | 82Sr | ||||||||
| 84Zr | 40 | 44 | 83.92325(21)# | 25.9(7) min | β+ | 84Y | 0+ | ||
| 85Zr | 40 | 45 | 84.92147(11) | 7.86(4) min | β+ | 85Y | 7/2+ | ||
| 85mZr | 292.2(3) keV | 10.9(3) s | IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... (92%) |
85Zr | (1/2-) | ||||
| β+ (8%) | 85Y | ||||||||
| 86Zr | 40 | 46 | 85.91647(3) | 16.5(1) h | β+ | 86Y | 0+ | ||
| 87Zr | 40 | 47 | 86.914816(9) | 1.68(1) h | β+ | 86Y | (9/2)+ | ||
| 87mZr | 335.84(19) keV | 14.0(2) s | IT | 87Zr | (1/2)- | ||||
| 88Zr | 40 | 48 | 87.910227(11) | 83.4(3) d | EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... |
88Y | 0+ | ||
| 89Zr | 40 | 49 | 88.908890(4) | 78.41(12) h | β+ | 89Y | 9/2+ | ||
| 89mZr | 587.82(10) keV | 4.161(17) min | IT (93.77%) | 89Zr | 1/2- | ||||
| β+ (6.23%) | 89Y | ||||||||
| 90ZrFission product Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The... |
40 | 50 | 89.9047044(25) | Stable | 0+ | 0.5145(40) | |||
| 90m1Zr | 2319.000(10) keV | 809.2(20) ms | IT | 90Zr | 5- | ||||
| 90m2Zr | 3589.419(16) keV | 131(4) ns | 8+ | ||||||
| 91Zr | 40 | 51 | 90.9056458(25) | Stable | 5/2+ | 0.1122(5) | |||
| 91mZr | 3167.3(4) keV | 4.35(14) µs | (21/2+) | ||||||
| 92Zr | 40 | 52 | 91.9050408(25) | StableHeaviest theoretically stable nuclide | 0+ | 0.1715(8) | |||
| 93ZrLong-lived fission product Long-lived fission product Long-lived fission products are radioactive materials with a long half-life produced by nuclear fission.-Evolution of radioactivity in nuclear waste:... |
40 | 53 | 92.9064760(25) | 1.53(10)×106 a | β- | 93Nb | 5/2+ | ||
| 94Zr | 40 | 54 | 93.9063152(26) | Observationally StableBelieved to decay by β-β- to 94Mo with a half-life over 1.1×1017 years | 0+ | 0.1738(28) | |||
| 95Zr | 40 | 55 | 94.9080426(26) | 64.032(6) d | β- | 95Nb | 5/2+ | ||
| 96ZrPrimordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma... |
40 | 56 | 95.9082734(30) | 20(4)×1018 a | β-β-Theorized to also undergo β- decay to 96Nb | 96Mo | 0+ | 0.0280(9) | |
| 97Zr | 40 | 57 | 96.9109531(30) | 16.744(11) h | β- | 97mNb | 1/2+ | ||
| 98Zr | 40 | 58 | 97.912735(21) | 30.7(4) s | β- | 98Nb | 0+ | ||
| 99Zr | 40 | 59 | 98.916512(22) | 2.1(1) s | β- | 99mNb | 1/2+ | ||
| 100Zr | 40 | 60 | 99.91776(4) | 7.1(4) s | β- | 100Nb | 0+ | ||
| 101Zr | 40 | 61 | 100.92114(3) | 2.3(1) s | β- | 101Nb | 3/2+ | ||
| 102Zr | 40 | 62 | 101.92298(5) | 2.9(2) s | β- | 102Nb | 0+ | ||
| 103Zr | 40 | 63 | 102.92660(12) | 1.3(1) s | β- | 103Nb | (5/2-) | ||
| 104Zr | 40 | 64 | 103.92878(43)# | 1.2(3) s | β- | 104Nb | 0+ | ||
| 105Zr | 40 | 65 | 104.93305(43)# | 0.6(1) s | β- (>99.9%) | 105Nb | |||
| β-, n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (<.1%) |
104Nb | ||||||||
| 106Zr | 40 | 66 | 105.93591(54)# | 200# ms [>300 ns] |
β- | 106Nb | 0+ | ||
| 107Zr | 40 | 67 | 106.94075(32)# | 150# ms [>300 ns] |
β- | 107Nb | |||
| 108Zr | 40 | 68 | 107.94396(64)# | 80# ms [>300 ns] |
β- | 108Nb | 0+ | ||
| 109Zr | 40 | 69 | 108.94924(54)# | 60# ms [>300 ns] |
|||||
| 110Zr | 40 | 70 | 109.95287(86)# | 30# ms [>300 ns] |
0+ | ||||