Iron-66

Properties and data of the isotope ⁶⁶Fe.

Contents

General data

Name of the isotope:Iron-66; Fe-66Symbol:⁶⁶Fe or 6626FeMass number A:66 (= number of nucleons)Atomic number Z:26 (= number of protons)Neutrons N:40Isotopic mass:65.946250(4) u (atomic weight of Iron-66)Nuclide mass:65.9319873 u (calculated nuclear mass without electrons)Mass excess:-50.0678 MeVMass defect:0.603797472 u (per nucleus)Nuclear binding energy:562.43372238 MeV (per nucleus)
8.52172307 MeV (average binding energy per nucleon)Separation energy:S_N = 6.921(7) MeV (first neutron)
S_P = 16.389(6) MeV (first proton)Half-life:440(60) msDecay constant λ:1.5753345012726 s^-1Specific activity α:1.459520964335 × 10⁺²² Bq g^-1
394465125496.14 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1985

Radioactive Decay

Half-life T_½ = 440(60) ms respectively 4.40 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁶⁶Co	100 %	6.341(15) MeV

Parent Nuclides

Direct parent isotope is: ⁶⁶Mn.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 40) and isobaric (same nucleon number A = 66) with Iron-66. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 40	Isobar A = 66
21	⁶¹Sc
22	⁶²Ti
23	⁶³V	⁶⁶V
24	⁶⁴Cr	⁶⁶Cr
25	⁶⁵Mn	⁶⁶Mn
26	⁶⁶Fe	⁶⁶Fe
27	⁶⁷Co	⁶⁶Co
28	⁶⁸Ni	⁶⁶Ni
29	⁶⁹Cu	⁶⁶Cu
30	⁷⁰Zn	⁶⁶Zn
31	⁷¹Ga	⁶⁶Ga
32	⁷²Ge	⁶⁶Ge
33	⁷³As	⁶⁶As
34	⁷⁴Se	⁶⁶Se
35	⁷⁵Br	⁶⁶Br
36	⁷⁶Kr
37	⁷⁷Rb
38	⁷⁸Sr
39	⁷⁹Y
40	⁸⁰Zr
41	⁸¹Nb
42	⁸²Mo