Catalysts for the petroleum and chemical industries, e.g.Cemented carbides (also called hard metals) and diamond tools.Superalloys, for parts in gas turbine aircraft engines.density measurements (e.g., concrete density measurements) andĬobalt-59 is used as a source in Mössbauer spectroscopy.industrial radiography (e.g., weld integrity radiographs).radiation treatment of foods for sterilization (cold pasteurization).sterilization of medical supplies, and medical waste.Industrial uses for radioactive isotopesĬobalt-60 (Co-60 or 60Co) is useful as a gamma ray source because it can be produced-in predictable quantity, and high activity-by simply exposing natural cobalt to neutrons in a reactor for a given time. The 60Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favor in the Western world where linacs are common.Ĭobalt-57 (Co-57 or 57Co) is a radioactive metal that is used in medical tests it is used as a radiolabel for vitamin B 12 uptake. The metal has the unfortunate habit of producing a fine dust, causing problems with radiation protection. The 60Co source is about 2 cm in diameter and as a result produces a geometric penumbra, making the edge of the radiation field fuzzy. It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV. The primary decay products before 59Co are element 26 ( iron) isotopes and the primary products after are element 28 ( nickel) isotopes.Ĭobalt-60 (Co-60 or 60Co) is a radioactive metal that is used in radiotherapy.
The primary decay mode for isotopes with atomic mass unit values less than that of the most abundant stable isotope, 59Co, is electron capture and the primary mode of decay for those of greater than 59 atomic mass units is beta decay. The isotopes of cobalt range in atomic weight from 50 u ( 50Co) to 73 u ( 73Co). This element also has 4 meta states, all of which have half-lives less than 15 minutes. All of the remaining radioactive isotopes have half-lives that are less than 18 hours and the majority of these have half-lives that are less than 1 second. 22 radioisotopes have been characterized with the most stable being 60Co with a half-life of 5.2714 years, 57Co with a half-life of 271.79 days, 56Co with a half-life of 77.27 days, and 58Co with a half-life of 70.86 days. Naturally occurring cobalt is "monoisotopic", i.e. Ĭommon oxidation states of cobalt include +2 and +3, although compounds with oxidation state +1 are also well developed. Cobalt has a hardness of 5.5 on the Mohs scale of mineral hardness. Metallic cobalt commonly presents a mixture of two crystallographic structures hcp and fcc with a transition temperature hcp→fcc of 722 K. Cobalt has a relative permeability two thirds that of iron. Cobalt-60, an artificially produced radioactive isotope of cobalt, is an important radioactive tracer and cancer-treatment agent. Mammals require small amounts of cobalt which is the basis of vitamin B 12. In nature, it is frequently associated with nickel, and both are characteristic ingredients of meteoric iron. The Curie temperature is of 1388 K with 1.6~1.7 Bohr magnetons per atom. Small amounts of it are found in most rocks, soil, water, plants, and animals. Pure cobalt is not found in nature, but compounds of cobalt occur naturally in many forms. 2.2 Industrial uses for radioactive isotopesĬobalt metal is a silver or gray ferromagnetic.Metallic with gray tinge Standard atomic weight
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