Isotopes of titanium

Naturally occurring titanium (₂₂Ti) is composed of five stable isotopes; ⁴⁶Ti, ⁴⁷Ti, ⁴⁸Ti, ⁴⁹Ti and ⁵⁰Ti with ⁴⁸Ti being the most abundant (73.8% natural abundance). Twenty-three radioisotopes have been characterized, with the most stable being ⁴⁴Ti with a half-life of 59.1 years and ⁴⁵Ti with a half-life of 184.8 minutes. All of the remaining radioactive isotopes have half-lives that are less than 10 minutes, and the majority of these have half-lives that are less than one second.

The isotopes of titanium range from ³⁹Ti to ⁶⁴Ti. The primary decay mode for isotopes lighter than the stable isotopes is β⁺ and the primary mode for the heavier ones is β^−; the decay products are respectively scandium isotopes and vanadium isotopes.

There are two stable isotopes of titanium with an odd number of nucleons, ⁴⁷Ti and ⁴⁹Ti, which thus have non-zero nuclear spin of 5/2− and 7/2− (respectively) and are NMR-active.

List of isotopes

|-id=Titanium-39 | rowspan=3|³⁹Ti | rowspan=3 style="text-align:right" | 22 | rowspan=3 style="text-align:right" | 17 | rowspan=3|39.00268(22)# | rowspan=3| | β⁺, p (93.7%) | ³⁸Ca | rowspan=3|3/2+# | rowspan=3| | rowspan=3| |- | β⁺ (~6.3%) | ³⁹Sc |- | β⁺, 2p (?%) | ³⁷K |-id=Titanium-40 | rowspan=2|⁴⁰Ti | rowspan=2 style="text-align:right" | 22 | rowspan=2 style="text-align:right" | 18 | rowspan=2|39.990345(73) | rowspan=2| | β⁺, p (95.8%) | ³⁹Ca | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺ (4.2%) | ⁴⁰Sc |-id=Titanium-41 | rowspan=2|⁴¹Ti | rowspan=2 style="text-align:right" | 22 | rowspan=2 style="text-align:right" | 19 | rowspan=2|40.983148(30) | rowspan=2| | β⁺, p (91.1%) | ⁴⁰Ca | rowspan=2|3/2+ | rowspan=2| | rowspan=2| |- | β⁺ (8.9%) | ⁴¹Sc |-id=Titanium-42 | ⁴²Ti | style="text-align:right" | 22 | style="text-align:right" | 20 | 41.97304937(29) | | β⁺ | ⁴²Sc | 0+ | | |-id=Titanium-43 | ⁴³Ti | style="text-align:right" | 22 | style="text-align:right" | 21 | 42.9685284(61) | | β⁺ | ⁴³Sc | 7/2− | | |-id=Titanium-43m1 | style="text-indent:1em" | ^43m1Ti | colspan="3" style="text-indent:2em" | | | IT | ⁴³Ti | (3/2+) | | |-id=Titanium-43m2 | style="text-indent:1em" | ^43m2Ti | colspan="3" style="text-indent:2em" | | | IT | ⁴³Ti | (19/2−) | | |- | ⁴⁴Ti | style="text-align:right" | 22 | style="text-align:right" | 22 | 43.95968994(75) | | EC | ⁴⁴Sc | 0+ | | |-id=Titanium-45 | ⁴⁵Ti | style="text-align:right" | 22 | style="text-align:right" | 23 | 44.95812076(90) | | β⁺ | ⁴⁵Sc | 7/2− | | |-id=Titanium-45m | style="text-indent:1em" | ^45mTi | colspan="3" style="text-indent:2em" | | | IT | ⁴⁵Ti | 3/2− | | |-id=Titanium-46 | ⁴⁶Ti | style="text-align:right" | 22 | style="text-align:right" | 24 | 45.952626356(97) | colspan=3 style="text-align:center;" data-sort-value=1e309 |Stable | 0+ | 0.0825(3) | |-id=Titanium-47 | ⁴⁷Ti | style="text-align:right" | 22 | style="text-align:right" | 25 | 46.951757491(85) | colspan=3 style="text-align:center;" data-sort-value=1e309 |Stable | 5/2− | 0.0744(2) | |-id=Titanium-48 | ⁴⁸Ti | style="text-align:right" | 22 | style="text-align:right" | 26 | 47.947940677(79) | colspan=3 style="text-align:center;" data-sort-value=1e309 |Stable | 0+ | 0.7372(3) | |-id=Titanium-49 | ⁴⁹Ti | style="text-align:right" | 22 | style="text-align:right" | 27 | 48.947864391(84) | colspan=3 style="text-align:center;" data-sort-value=1e309 |Stable | 7/2− | 0.0541(2) | |-id=Titanium-50 | ⁵⁰Ti | style="text-align:right" | 22 | style="text-align:right" | 28 | 49.944785622(88) | colspan=3 style="text-align:center;" data-sort-value=1e309 |Stable | 0+ | 0.0518(2) | |-id=Titanium-51 | ⁵¹Ti | style="text-align:right" | 22 | style="text-align:right" | 29 | 50.94660947(52) | | β^− | ⁵¹V | 3/2− | | |-id=Titanium-52 | ⁵²Ti | style="text-align:right" | 22 | style="text-align:right" | 30 | 51.9468835(29) | | β^− | ⁵²V | 0+ | | |-id=Titanium-53 | ⁵³Ti | style="text-align:right" | 22 | style="text-align:right" | 31 | 52.9496707(31) | | β^− | ⁵³V | (3/2)− | | |-id=Titanium-54 | ⁵⁴Ti | style="text-align:right" | 22 | style="text-align:right" | 32 | 53.950892(17) | | β^− | ⁵⁴V | 0+ | | |-id=Titanium-55 | ⁵⁵Ti | style="text-align:right" | 22 | style="text-align:right" | 33 | 54.955091(31) | | β^− | ⁵⁵V | (1/2)− | | |-id=Titanium-56 | ⁵⁶Ti | style="text-align:right" | 22 | style="text-align:right" | 34 | 55.95768(11) | | β^− | ⁵⁶V | 0+ | | |-id=Titanium-57 | ⁵⁷Ti | style="text-align:right" | 22 | style="text-align:right" | 35 | 56.96307(22) | | β^− | ⁵⁷V | 5/2−# | | |-id=Titanium-58 | ⁵⁸Ti | style="text-align:right" | 22 | style="text-align:right" | 36 | 57.96681(20) | | β^− | ⁵⁸V | 0+ | | |-id=Titanium-59 | ⁵⁹Ti | style="text-align:right" | 22 | style="text-align:right" | 37 | 58.97222(32)# | | β^− | ⁵⁹V | 5/2−# | | |-id=Titanium-59m | style="text-indent:1em" | ^59mTi | colspan="3" style="text-indent:2em" | | | IT | ⁵⁹Ti | 1/2−# | | |-id=Titanium-60 | ⁶⁰Ti | style="text-align:right" | 22 | style="text-align:right" | 38 | 59.97628(26) | | β^− | ⁶⁰V | 0+ | | |-id=Titanium-61 | ⁶¹Ti | style="text-align:right" | 22 | style="text-align:right" | 39 | 60.98243(32)# | | β^− | ⁶¹V | 1/2−# | | |-id=Titanium-61m1 | style="text-indent:1em" | ^61m1Ti | colspan="3" style="text-indent:2em" | | | IT | ⁶¹Ti | 5/2−# | | |-id=Titanium-61m2 | style="text-indent:1em" | ^61m2Ti | colspan="3" style="text-indent:2em" | | | IT | ⁶¹Ti | 9/2+# | | |-id=Titanium-62 | ⁶²Ti | style="text-align:right" | 22 | style="text-align:right" | 40 | 61.98690(43)# | [>620 ns] | | | 0+ | | |-id=Titanium-63 | ⁶³Ti | style="text-align:right" | 22 | style="text-align:right" | 41 | 62.99371(54)# | [>620 ns] | | | 1/2−# | | |-id=Titanium-64 | ⁶⁴Ti | style="text-align:right" | 22 | style="text-align:right" | 42 | 63.99841(64)# | [>620 ns] | | | 0+ | | |-id=Titanium-65 | ⁶⁵Ti | style="text-align:right" | 22 | style="text-align:right" | 43 | 65.00559(75)# | | | | 1/2−# | |-id=Titanium-66 | ⁶⁶Ti | style="text-align:right" | 22 | style="text-align:right" | 44 | | | | | 0+ |

Titanium-44

Titanium-44 (⁴⁴Ti) is a radioactive isotope of titanium that undergoes electron capture with a half-life of 59.1 years to an excited state of scandium-44, before reaching the ground state of ⁴⁴Sc and ultimately of ⁴⁴Ca. Because titanium-44 can decay only through electron capture, its half-life increases slowly with its ionization state and it becomes stable in its fully ionized state (that is, having a charge of +22), though as astrophysical environments never lack electrons completely, it will always decay.

Titanium-44 is produced in relative abundance in the alpha process in stellar nucleosynthesis and the early stages of supernova explosions. It is produced when stable calcium-40 adds an alpha particle (helium-4), as nickel-56 is the result of adding three more. The age of supernova remnants (even though nickel-56 has died away to iron) may be determined through measurements of gamma-ray emissions from the relatively long-lived titanium-44 and of its abundance. It was observed in the Cassiopeia A supernova remnant and SN 1987A at a relatively high concentration, enhanced by the delayed decay in the ionizing conditions.

See also

Daughter products other than titanium

• Isotopes of vanadium
• Isotopes of scandium
• Isotopes of calcium
• Isotopes of potassium

References