Iron-57

Properties and data of the isotope ⁵⁷Fe.

Content

General data

Name of the isotope:Iron-57; Fe-57Symbol:⁵⁷Fe or 5726FeMass number A:57 (= number of nucleons)Atomic number Z:26 (= number of protons)Neutrons N:31Isotopic mass:56.935393(3) u (atomic weight of Iron-57)Nuclide mass:56.9211303 u (calculated nuclear mass without electrons)Mass excess:-60.18103 MeVMass defect:0.536670228 u (per nucleus)Nuclear binding energy:499.90509736 MeV (per nucleus)
8.77026487 MeV (average binding energy per nucleon)Separation energy:S_N = 7.64607(4) MeV (first neutron)
S_P = 10.55927(21) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2-Isobaric spin: 5/2Magnetic dipole moment:μ(μ_N) = +0.09064(7)Charge radius:3.7532(17) femtometer fmYear of discovery:1935

Parent Nuclides

Direct parent isotopes are: ⁵⁷Co, ⁵⁷Mn.

Occurrence

Comparison of the natural Iron isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Iron Isotopic mixture	55.845 u	100 %
Isotope ⁵⁴Fe	53.939609(3) u	5.845(105) %	stable	0+
Isotope ⁵⁶Fe	55.934936(3) u	91.754(106) %	stable	0+
Isotope ⁵⁷Fe	56.935393(3) u	2.119(29) %	stable	1/2-
Isotope ⁵⁸Fe	57.933274(3) u	0.282(12) %	stable	0+

NMR data

Nuclear magnetic properties of the NMR active Nuclide ⁵⁷Fe

Isotope:⁵⁷Fe-NMRQuantity:2.119(29) %Spin:1/2-Nuclearmagnetic moment
μ/μ_N:+0.09064(7)Gyromagnetic ratio γ:0.8661 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = 0.18128Quadrupole moment Q:+ 0.160 barn (100 fm²)Resonance frequency:v₀ = 1.3816 at 1 TRelative Sensitivity:0.00003 (H₀ = const.)
0.0324 (v₀ = const.)
[related to ¹H = 1.000]

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 31) and isobaric (same nucleon number A = 57) with Iron-57. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 31	Isobar A = 57
15	⁴⁶P
16	⁴⁷S
17	⁴⁸Cl
18	⁴⁹Ar
19	⁵⁰K
20	⁵¹Ca	⁵⁷Ca
21	⁵²Sc	⁵⁷Sc
22	⁵³Ti	⁵⁷Ti
23	⁵⁴V	⁵⁷V
24	⁵⁵Cr	⁵⁷Cr
25	⁵⁶Mn	⁵⁷Mn
26	⁵⁷Fe	⁵⁷Fe
27	⁵⁸Co	⁵⁷Co
28	⁵⁹Ni	⁵⁷Ni
29	⁶⁰Cu	⁵⁷Cu
30	⁶¹Zn	⁵⁷Zn
31	⁶²Ga
32	⁶³Ge
33	⁶⁴As
34	⁶⁵Se
35	⁶⁶Br
36	⁶⁷Kr