Talk:Isotopes of europium

Low Half-life values of OO63Eu144 and OO63Eu140

The reported half-lives do not agree with the half-life trend line of the rest of the 63Eu Europium OO type isotopes.WFPM (talk) 23:42, 21 April 2013 (UTC)

How would ¹⁵³
Eu decay to a much less stable isotope, ¹⁴⁹
Pm?

Because ¹⁴⁹
Pm is way too unstable, so shouldn't ¹⁵³
Eu be stable too? 80.98.179.160 (talk) 07:06, 26 March 2018 (UTC)

This is pretty normal: the obvious example is that ²³⁸U (half-life 4.468 × 10⁹ years) decays to ²³⁴Th (half-life 24.1 days). The important thing is that the system of ¹⁴⁹Pm plus an alpha particle is a lower-energy arrangement of 63 protons and 90 neutrons than a single ¹⁵³Eu nucleus (just look at the binding energies), and so the decay is energetically allowed. Of course, it is kinetically hindered for other reasons. The beta-instability of ¹⁴⁹Pm has nothing to do with it. Double sharp (talk) 07:15, 26 March 2018 (UTC)

It may be worth noted that ¹⁴⁹Pm also has a greater alpha decay energy (1.135 MeV) than that of ¹⁵³Eu (0.273 MeV). Roughly speaking, ¹⁴⁹Pm havs 3 more protons than the alpha-stable nuclide ¹⁴⁶Ce, while ¹⁵³Eu has only 2 more protons than the alpha-stable ¹⁵¹Pm.

In the example of ²³⁸U-²³⁴Th this is not the case (4.270 MeV for ²³⁸U vs. 3.672 MeV for ²³⁴Th). Of course lower alpha decay energy does not necessarily mean longer alpha decay partial half-life: ²³¹Th has an alpha decay energy of 4.213 MeV and partial half-life 2.91×10⁷ years, compared to 4.678 MeV and 7.04×10⁸ years for ²³⁵U. 129.104.241.214 (talk) 00:55, 24 November 2023 (UTC)

Because ¹⁵³Eu have a larger mass than a combination of ¹⁴⁹Pm and ⁴He (atomic mass of ¹⁵³Eu is 152.9212303, atomic mass of ¹⁴⁹Pm is 148.918334, atomis of ⁴He is 4.002602) but the kenetic energy of alpha particle in this case is quite small meaning the half-life is quite largeCristiano Toàn (talk) 08:54, 16 May 2022 (UTC)

At the order of 10¹⁴⁰ year as stated in [1]. 129.104.241.214 (talk) 06:25, 28 October 2023 (UTC)

Theoretical decay chain of ¹⁵³Eu:¹⁵³Eu => ¹⁴⁹Pm => ¹⁴⁹Sm => ¹⁴⁵Nd => ¹⁴¹Ce => ¹⁴¹Pm (the last nuclide contains 82 neutrons, magic number). Both ¹⁴⁹Sm and ¹⁴⁵Nd has theoretical half-life shorter than ¹²⁸Te's half-life

Could ¹⁵⁰Eu possibly undergo β- decay to ¹⁵⁰Gd?

This is energetically allowed, and also we observe a 89% probability of the β- decay of ^150mEu. However, just like to case of ⁹⁸Tc whose decay to ⁹⁸Mo is unknown, do we know that it is impossible, or it's just we haven't observed that mode of decay? 129.104.241.214 (talk) 00:26, 11 October 2023 (UTC) Cristiano Toàn (talk) 14:37, 11 February 2024 (UTC). Cristiano Toàn (talk) 14:37, 11 February 2024 (UTC)Theoretical decay chain of ¹⁵³Eu:¹⁵³Eu => ¹⁴⁹Pm => ¹⁴⁹Sm => ¹⁴⁵Nd => ¹⁴¹Ce => ¹⁴¹Pm (the last nuclide contains 82 neutrons, magic number). Both ¹⁴⁹Sm and ¹⁴⁵Nd has theoretical half-life shorter than ¹²⁸Te's half-life

Possible alpha decay of ^{144,145,146,149}Eu

According to [2], ¹⁴⁶Eu (N = 83) and ¹⁴⁹Eu (N = 86) should respectively have a partial alpha decay half-life of at least 10²² years and 10⁹ years. ¹⁴⁹Eu has similar alpha decay energy as its decay product (2.40 MeV for ¹⁴⁹Eu and 2.32 MeV for ¹⁴⁵Pm), and ¹⁴⁶Eu has lower decay energy than ¹⁵¹Eu (1.60 MeV vs. 1.96 MeV).

As for ¹⁴⁴Eu (N = 81) and ¹⁴⁵Eu (N = 82), they have respectively an alpha decay energy of 0.16 MeV and 0.10 MeV, which are much too low, so their partial alpha decay half-lives should be long beyond imagination. 129.104.241.214 (talk) 06:14, 24 October 2023 (UTC)