Across the chart of nuclides and in labs that measure nuclear properties, cobalt shows a compact but interesting set of species that matter for research and applications. Whether you’re checking decay data for experiments or looking up sources used in medicine and industry, a concise list helps you compare them quickly.
There are 9 Cobalt Isotopes, ranging from Co-55 to Co-64; for each, you’ll find below Half-life (s),Decay mode (product),Spin (ħ) so you can scan stability, decay pathways, and nuclear spin at a glance—you’ll find those details below.
Which cobalt isotope is stable and which are most used?
Co-59 is the only stable cobalt isotope; the others are radioactive with half-lives that range from seconds up to years. Co-60 is the longest-lived and most used radioactive isotope (industrial radiography, sterilization, some medical uses), while shorter-lived nuclides like Co-55 serve as tracers in research and imaging applications.
How do I read the columns in the list?
Half-life (s) gives the decay time in seconds (so very short and long lives are comparable), Decay mode (product) names how the nucleus decays and the resulting nuclide, and Spin (ħ) lists the nuclear spin in units of the reduced Planck constant—useful when comparing nuclear states or planning spectroscopy experiments.
Cobalt Isotopes
| Isotope | Half-life (s) | Decay mode (product) | Spin (ħ) |
|---|---|---|---|
| Co-55 | 63,108 s | Electron capture / β+ (Fe-55) | 7/2- |
| Co-56 | 6,676,128 s | Electron capture (Fe-56) | 3+ |
| Co-57 | 23,482,656 s | Electron capture (Fe-57) | 7/2- |
| Co-58 | 6,122,304 s | Electron capture / β+ (Fe-58) | 2+ |
| Co-59 | stable | Stable (none) | 7/2- |
| Co-60 | 166,000,000 s | β- (Ni-60) | 5+ |
| Co-61 | 5,940 s | β+ /Electron capture (Fe-61) | 3/2+ |
| Co-62 | 540 s | β+ /Electron capture (Fe-62) | 1+ |
| Co-64 | 4.32 s | β+ /β- (Fe-64 / Ni-64) | 1+ |
Images and Descriptions
Co-55
A positron/emitter produced in cyclotrons for research and tracer studies; useful for imaging and chemistry studies. Moderate half-life suits lab use; decays to stable iron-55 with emitted gammas useful for detection.
Co-56
Produced in nuclear reactions and observed in supernova decay chains, Co-56 decays to stable iron-56. It’s notable in astrophysics for powering early supernova light curves and for experiments studying nuclear structure.
Co-57
A long-lived gamma emitter widely used as a calibration and Mössbauer source; Co-57 decays to Fe-57 and is valued in medical imaging calibration and materials analysis due to its well-known gamma lines.
Co-58
A neutron-deficient isotope produced in accelerators and reactors used for nuclear-structure studies. Co-58 decays toward iron-58 and has been important historically for activation analysis and experimental cross-section measurements.
Co-59
The only naturally stable cobalt isotope and the only one occurring as primordial cobalt. It forms the basis of chemical cobalt and is the isotope found in nature; important for elemental chemistry and stable-isotope studies.
Co-60
Famous industrial and medical radioisotope used for radiotherapy, sterilization, and radiography. Produced by neutron activation of Co-59 in reactors, Co-60 emits strong gamma rays and has a multi-year half-life useful for long-term sources.
Co-61
Short-lived isotope made in accelerator experiments; used mainly for nuclear-structure and decay-scheme studies. Its brief lifetime limits applications but provides data on decay modes and excited nuclear states.
Co-62
A short-lived, proton-rich isotope often produced in fragmentation or spallation for experimental nuclear physics. Its rapid decay to iron isotopes helps map energy levels and reaction pathways in light nuclei.
Co-64
Very short-lived isotope observed in laboratory settings, used for studying extreme proton-rich or neutron-rich decay channels. Its fleeting existence provides insight into nuclear forces and shell effects near stability.
