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Isotopes of Hafnium

List, data and properties of all known isotopes of Hafnium as well as radioactive decay products and intermediate products.

 

Hafnium isotopes

All atomic nuclei of the chemical element hafnium are summarized under hafnium isotopes; these all consist of an atomic nucleus with 72 protons and, in the uncharged state, 72 electrons. The difference between each hafnium isotope is based on the number of neutrons in the nucleus.

 

Naturally Occurring Hafnium Isotopes

The natural terrestrial hafnium deposits consist of a mixture of 6 different isotopes: the stable hafnium nuclides Hf-176, 177, 178, 179 and 180 as well as the slightly radioactive, very long-lived radioisotope Hf-174. Overall, the isotope distribution for hafnium is as follows:

Atomic Mass maQuantityHalf-lifeSpin
Hafnium
Isotopic mixture
178,486 u100 %
Isotope 174Hf173,94005(2) u0,16(12) %2.0(4) × 1015 a0+
Isotope 176Hf175,94141(2) u5,26(70) %stable0+
Isotope 177Hf176,94323(2) u18,60(16) %stable7/2-
Isotope 178Hf177,94371(2) u27,28(28) %stable0+
Isotope 179Hf178,94582(2) u13,62(11) %stable9/2+
Isotope 180Hf179,94656(2) u35,08(33) %stable0+

 

Hafnium-182 is the most stable artificial hafnium isotope with a half-life of 9,000,000 years. There are no technical applications for individual hafnium isotopes.

 

Isotope Table: Hafnium

 

Atomic Properties

Isotope
Nuclide
ZANNameAtomic Mass
[Nuclear Mass]
{Mass Excess}
Spin I
(h/2π)
μParent
123456789
153Hf7215381Hafnium-153152.97069(32) u
[152.931196 u]
{-27.30209 MeV}
154Hf7215482Hafnium-154153.96493(32) u
[153.925436 u]
{-32.66749 MeV}
0+158W
155Hf7215583Hafnium-155154.96332(32) u
[154.923826 u]
{-34.1672 MeV}
159W
156Ta
156Hf7215684Hafnium-156155.95940(16) u
[155.919906 u]
{-37.81866 MeV}
0+160W
156Ta
156mHf7215684Hafnium-156m155.95940(16) u
[155.919906 u]
{-37.81866 MeV}
8+
157Hf7215785Hafnium-157156.95824(21) u
[156.918746 u]
{-38.89919 MeV}
(7/2-)161W
158Hf7215886Hafnium-158157.954801(19) u
[157.915307 u]
{-42.1026 MeV}
0+162W
159Hf7215987Hafnium-159158.953996(18) u
[158.914502 u]
{-42.85245 MeV}
7/2-163W
160Hf7216088Hafnium-160159.950683(10) u
[159.911189 u]
{-45.93849 MeV}
0+164W
161Hf7216189Hafnium-161160.950279(24) u
[160.910785 u]
{-46.31481 MeV}
(7/2-)165W
161mHf7216189Hafnium-161m160.950279(24) u
[160.910785 u]
{-46.31481 MeV}
(13/2+)
162Hf7216290Hafnium-162161.947215(10) u
[161.907721 u]
{-49.16891 MeV}
0+166W
162Ta
163Hf7216391Hafnium-163162.947113(27) u
[162.907619 u]
{-49.26392 MeV}
(5/2-)167W
163Ta
164Hf7216492Hafnium-164163.944371(17) u
[163.904877 u]
{-51.81808 MeV}
0+168W
164Ta
165Hf7216593Hafnium-165164.94457(3) u
[164.905076 u]
{-51.63271 MeV}
(5/2-)165Ta
166Hf7216694Hafnium-166165.94218(3) u
[165.902686 u]
{-53.85898 MeV}
0+166Ta
167Hf7216795Hafnium-167166.94260(3) u
[166.903106 u]
{-53.46776 MeV}
(5/2)-167Ta
168Hf7216896Hafnium-168167.94057(3) u
[167.901076 u]
{-55.35869 MeV}
0+168Ta
169Hf7216997Hafnium-169168.94126(3) u
[168.901766 u]
{-54.71596 MeV}
5/2-169Ta
170Hf7217098Hafnium-170169.93961(3) u
[169.900116 u]
{-56.25292 MeV}
0+170Ta
171Hf7217199Hafnium-171170.94049(3) u
[170.900996 u]
{-55.43321 MeV}
7/2(+)- 0.674(12)171Ta
171mHf7217199Hafnium-171m170.94049(3) u
[170.900996 u]
{-55.43321 MeV}
1/2(-)+ 0.526(16)
172Hf72172100Hafnium-172171.939450(26) u
[171.899956 u]
{-56.40196 MeV}
0+172Ta
172mHf72172100Hafnium-172m171.939450(26) u
[171.899956 u]
{-56.40196 MeV}
(8-)+7.95(7)
173Hf72173101Hafnium-173172.94051(3) u
[172.901016 u]
{-55.41458 MeV}
1/2-173Ta
174Hf72174102Hafnium-174173.94005(2) u
[173.900556 u]
{-55.84307 MeV}
0+174Ta
175Hf72175103Hafnium-175174.9415115(24) u
[174.9020175 u]
{-54.48169 MeV}
5/2(-)- 0.539(32)175Ta
176Hf72176104Hafnium-176175.94141(2) u
[175.901916 u]
{-54.57623 MeV}
0+176Ta
176Lu
177Hf72177105Hafnium-177176.94323(2) u
[176.903736 u]
{-52.88091 MeV}
7/2-+ 0.7935177Ta
177Lu
177m1Hf72177105Hafnium-177m1176.94323(2) u
[176.903736 u]
{-52.88091 MeV}
23/2+
177m2Hf72177105Hafnium-177m2176.94323(2) u
[176.903736 u]
{-52.88091 MeV}
(19/2-)
177m3Hf72177105Hafnium-177m3176.94323(2) u
[176.903736 u]
{-52.88091 MeV}
37/2-7.33(9)
178Hf72178106Hafnium-178177.94371(2) u
[177.904216 u]
{-52.4338 MeV}
0+178Ta
178Lu
178m1Hf72178106Hafnium-178m1177.94371(2) u
[177.904216 u]
{-52.4338 MeV}
8-
178m2Hf72178106Hafnium-178m2177.94371(2) u
[177.904216 u]
{-52.4338 MeV}
16+
179Hf72179107Hafnium-179178.94582(2) u
[178.906326 u]
{-50.46834 MeV}
9/2+- 0.60409(13)179Ta
179Lu
179m1Hf72179107Hafnium-179m1178.94582(2) u
[178.906326 u]
{-50.46834 MeV}
1/2-
179m2Hf72179107Hafnium-179m2178.94582(2) u
[178.906326 u]
{-50.46834 MeV}
25/2-7.4(3)
180Hf72180108Hafnium-180179.94656(2) u
[179.907066 u]
{-49.77904 MeV}
0+180Ta
180Lu
180mHf72180108Hafnium-180m179.94656(2) u
[179.907066 u]
{-49.77904 MeV}
8-+ 8.7(10)
181Hf72181109Hafnium-181180.9491110(15) u
[180.909617 u]
{-47.4028 MeV}
1/2-181Lu
182Hf72182110Hafnium-182181.950564(7) u
[181.91107 u]
{-46.04934 MeV}
0+182Lu
182mHf72182110Hafnium-182m181.950564(7) u
[181.91107 u]
{-46.04934 MeV}
(8-)
183Hf72183111Hafnium-183182.95353(3) u
[182.914036 u]
{-43.28653 MeV}
(3/2-)183Lu
184Hf72184112Hafnium-184183.95545(4) u
[183.915956 u]
{-41.49806 MeV}
0+184Lu
184mHf72184112Hafnium-184m183.95545(4) u
[183.915956 u]
{-41.49806 MeV}
(8-)
185Hf72185113Hafnium-185184.95886(7) u
[184.919366 u]
{-38.32166 MeV}
186Hf72186114Hafnium-186185.96090(5) u
[185.921406 u]
{-36.42142 MeV}
0+
187Hf72187115Hafnium-187186.96477(32) u
[186.925276 u]
{-32.81653 MeV}
188Hf72188116Hafnium-188187.96685(32) u
[187.927356 u]
{-30.87903 MeV}
0+
189Hf72189117Hafnium-189188.97084(32) u
[188.931346 u]
{-27.16237 MeV}
190Hf72190118Hafnium-190189.97313(43) u
[189.933636 u]
{-25.02924 MeV}
0+

 

Radioactive Decay Properties

IsotopeRadioactive DecayAEExtern
Half-lifeDecay ModeProbabilityEnergy
1101112131415
Hf-15360 nsAL
Hf-1542(1) sEC/β+154Lu
α → 150Yb
ca. 100 %
ca. 0 %
7.04(36) MeV
3.54(42) MeV
AL
Hf-1550.89(12) sEC/β+155Lu100 %8.38(30) MeVAL
Hf-15623(1) msα → 152Yb100 %6.029(4) MeVAL
Hf-156m0.52(1) msα → 152Yb100 %1959(6) keVAL
Hf-157115(1) msEC/β+157Lu
α → 153Yb
14(9) %
86(9) %
7.54(20) MeV
5.880(3) MeV
AL
Hf-1582.85(7) sEC/β+158Lu
α → 154Yb
55.7(19) %
44.3(19) %
5.110(23) MeV
5.4048(27) MeV
AL
Hf-1595.6(4) sEC/β+159Lu
α → 155Yb
65(7) %
35(7) %
6.86(4) MeV
5.2251(27) MeV
AL
Hf-16013.6(2) sEC/β+160Lu
α → 156Yb
99.3(2) %
0.7(2) %
4.33(6) MeV
4.9019(26) MeV
AL
Hf-16118.4(4)sEC/β+161Lu
α → 157Yb
> 99.87 %
< 0.13 %
6.25(4) MeV
4.682(24) MeV
AL
Hf-161m4.8(2) μsIso → 161Hf100 %329.0(5) keV
Hf-16239.4(9) sEC/β+162Lu
α → 158Yb
99.992(1) %
0.008(1) %
3.66(8) MeV
4.416(5) MeV
AL
Hf-16340.0(6) sEC/β+163Lu
α → 159Yb
> 99.9998 %
< 0.0001 %
5.53(4) MeV
4.15(3) MeV
AL
Hf-164111(8) sEC/β+164Lu100 %2.82(3) MeVAL
Hf-16576(4) sEC/β+165Lu100 %4.81(4) MeVAL
Hf-1666.77(30) minEC/β+166Lu100 %2.16(4) MeVAL
Hf-1672.05(5) minEC/β+167Lu100 %4.03(4) MeVAL
Hf-16825.95(20) minEC/β+168Lu100 %1.71(5) MeVAL
Hf-1693.24(4) minEC/β+169Lu100 %3.368(28) MeVAL
Hf-17016.01(13) hEC → 170Lu100 %1.05(3) MeVAL
Hf-17112.1(4) hEC/β+171Lu100 %2.397(29) MeVAL
Hf-171m29.5(9) sEC/β+171Lu
Iso → 171Hf
?
≤ 100 %

21.93(9) keVAL
Hf-1721.87(3) aEC → 172Lu100 %0.334(25) MeVAL
Hf-172m163(3) nsIso → 172Hf2005.84(11) keV
Hf-17323.6(1) hEC/β+173Lu100 %1.469(28) MeVAL
Hf-1742.0(4) × 1015 aα → 170Yb100 %2.4945(23) MeVAL
Hf-17570(2) dEC → 175Lu100 %0.6839(26) MeVAL
Hf-176stableAL
Hf-177stableAL
Hf-177m11.09(5) sIso → 177Hf100 %1315.4502(8) keV
Hf-177m255.9(12) μs1342.4(10) keV
Hf-177m351.4(5) minIso → 177Hf100 %2740.02(15) keV
Hf-178stableAL
Hf-178m14.0(2) sIso → 178Hf100 %1147.416(6) keV
Hf-178m231(1) aIso → 178Hf100 %2446.09(8)
Hf-179stableAL
Hf-179m118.67(4) sIso → 179Hf100 %375.0352(25) keV
Hf-179m225.05(25) dIso → 179Hf100 %1105.74(16) kev
Hf-180stableAL
Hf-180m5.53(2) hIso → 180Hf
β-180Ta
99.7(1) %
0.3(1) %

1141.50(5)
Hf-18142.39 dβ-181Ta100 %1.0355(18) MeVAL
Hf-1828.90(9) × 106 aβ-182Ta100 %0.380(6) MeVAL
Hf-182m61.5(15) minβ-182Ta
Iso → 182Hf
54(2) %
46(2) %

1172.87(18) keV
Hf-1831.018(2) hβ-183Ta100 %2.01(3) MeVAL
Hf-1844.12(5) hβ-184Ta100 %1.34(3) MeVAL
Hf-184m48(10) sIso → 184Hf100 %1272.2(4)
Hf-1853.5(6) minβ-185Ta100 %3.07(7) MeVAL
Hf-1862.6(12) minβ-186Ta100 %2.18(8) MeVAL
Hf-187β-187Ta100 %4.08(30) MeVAL
Hf-188β-188Ta100 %2.73(30) MeVAL
Hf-189> 300 nsβ-189Ta100 %4.67(36) MeVAL
Hf-190160 nsβ-190Ta?3.48(45) MeV

 

Notes (related to the columns):

1 - nuclide, isotope symbol.
2 - Z = number of protons (atomic number).
3 - Mass number A.
4 - N = number of neutrons.
5 - Identification of the Hafnium isotope.
6 - Relative atomic mass of the Hafnium isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
7 - Nuclear spin I, unit: h/2π.
8 - Nuclear magnetic moment μmag.
9 - Source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
10 - Decay: Half-live of the Hafnium isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
11 - Decay: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
12 - Decay percentage in percent (%).
13 - Decay energy; Particle energy related to decay type.
14 - AE = Excitation energy for metastable nuclei.
15 - Other information and notes: AL = Adopted Levels (link to external data [1]).

Miscellaneous:

()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
  - unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.

 

NMR active Hafnium nuclides

Nuclide
quantity 1)
spin
Nuclear magnetic
moment
μ/μN
Gyromagnetic
ratio
107 rad T-1 s-1
Quadrupole
moment
Q fm-2
Resonant
frequency
v0 bei 1 T
Relative
sensitivity
H0 = const.
v0 = const. 2)
177Hf
18,60(16) %
7/2-
+ 0,79351,086+ 336,5(29)1,72820,00140
0,8524
179Hf
13,62(11) %
9/2+
- 0,60409(13)0,6821+ 379,3(33)1,08560,00055
0,8414

1) Quantity Percentage of natural occurrence.

2) Related to 1H = 1,000.

 

Radiation Protection

According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Hafnium radionuclides:

NuclideLimit ValueHASS limitSCDaughter NuclidesHalf-life
Hf-170+106 Bq100 Bq/g16.0 h
Hf-172+106 Bq1 Bq/g0,04 TBq1.9 a
Hf-173106 Bq100 Bq/g23.9 h
Hf-175106 Bq1 Bq/g0,2 TBq70.0 d
Hf-177m+105 Bq10 Bq/g51.4 min
Hf-178m+106 Bq0,1 Bq/g31.0 a
Hf-179m106 Bq10 Bq/g25.0 d
Hf-180m106 Bq10 Bq/g5.5 h
Hf-181106 Bq1 Bq/g0,1 TBq1 Bq cm-242.4 d
Hf-182+106 Bq0,1 Bq/g0,05 TBq9000000 a
Hf-182m+106 Bq10 Bq/g61.5 min
Hf-183106 Bq10 Bq/g64.0 min
Hf-184106 Bq100 Bq/g4.1 h

(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)

 

Literature Sources and References

Properties of the Hafnium nucleides

[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.

[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.

[3] - Live Chart of Nuclides. Nuclear structure and decay data.

Hafnium: NMR properties - 177Hf-NMR, 179Hf-NMR

[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.

[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.

[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.

[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).

More sources:

[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.

[9] - J. L. Gross, M. Thoennessen:
Discovery of gallium, germanium, lutetium, and hafnium isotopes.
In: Atomic Data and Nuclear Data Tables, (2012), DOI 10.1016/j.adt.2011.09.004.

 


Category: Isotopes

Last update: 05.07.2020



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