Unstable copper isotopes with atomic masses below 63 tend to undergo β+ decay, while isotopes with atomic masses above 65 tend to undergo β− decay.
Both stable isotopes of copper (63Cu and 65Cu) have nuclear spin of 3/2−, and thus produce nuclear magnetic resonance spectra, although the spectral lines are broad due to quadrupolar broadening.
[8] Copper offers a relatively large number of radioisotopes that are potentially useful for nuclear medicine.
There is growing interest in the use of 64Cu, 62Cu, 61Cu, and 60Cu for diagnostic purposes and 67Cu and 64Cu for targeted radiotherapy.
For example, 64Cu has a longer half-life than most positron-emitters (12.7 hours) and is thus ideal for diagnostic PET imaging of biological molecules.