Isotopes of iridium

There are two natural isotopes of iridium (₇₇Ir), ¹⁹¹Ir and ¹⁹³Ir, both stable. In addition, there are 40 known radioisotopes with mass numbers 164 through 205, the most stable being ¹⁹²Ir with a half-life of 73.82 days, and many nuclear isomers, the most stable of which is ^192m2Ir with a half-life of 241 years. All other nuclides have half-lives under two weeks, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

The isotope ¹⁹¹Ir was the first one of any element to be shown to present a Mössbauer effect. This renders it useful for Mössbauer spectroscopy for research in physics, chemistry, biochemistry, metallurgy, and mineralogy.

List of isotopes

|-id=Iridium-164 | ¹⁶⁴Ir | style="text-align:center;" rowspan=122 | 77 | rowspan="3" style="text-align:right" | 87 | style="text-align:center;" | | | p? | ¹⁶³Os | 2# | | |-id=Iridium-164m | rowspan=2 style="text-indent:1em" | ^164mIr | rowspan=2 style="text-align:center;" | <br/>260(100)#&nbsp;keV | rowspan=2| | p (96%) | ¹⁶³Os | rowspan=2| (9+) | rowspan=2| | rowspan=2| |- | α (4%) | ^160mRe |-id=Iridium-165 | ¹⁶⁵Ir |rowspan="3" style="text-align:right" | 88 | style="text-align:center;" | | | p | ¹⁶⁴Os | (1/2+) | | |-id=Iridium-165m | rowspan=2 style="text-indent:1em" | ^165mIr | rowspan=2 style="text-align:center;" | <br/>~255&nbsp;keV | rowspan=2| | p (88%) | ¹⁶⁴Os | rowspan=2|(11/2) | rowspan=2| | rowspan=2| |- | α (12%) | ^161mRe |-id=Iridium-166 | rowspan=2|¹⁶⁶Ir | rowspan="4" style="text-align:right" | 89 | rowspan=2 style="text-align:center;" | | rowspan=2| | α (93%) | ¹⁶²Re | rowspan=2|(2) | rowspan=2| | rowspan=2| |- | p (7%) | ¹⁶⁵Os |-id=Iridium-166m | rowspan=2 style="text-indent:1em" | ^166mIr | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | α (98.2%) | ¹⁶²Re | rowspan=2|(9)+ | rowspan=2| | rowspan=2| |- | p (1.8%) | ¹⁶⁵Os |-id=Iridium-167 | rowspan=3|¹⁶⁷Ir | rowspan="6" style="text-align:right" | 90 | rowspan=3 style="text-align:center;" | | rowspan=3| | α (43.5%) | ¹⁶³Re | rowspan=3|1/2+ | rowspan=3| | rowspan=3| |- | p (38.6%) | ¹⁶⁶Os |- | β⁺ (17.9%) | ¹⁶⁷Os |-id=Iridium-167m | rowspan=3 style="text-indent:1em" | ^167mIr | rowspan=3 style="text-align:center;" | <br/> | rowspan=3| | α (89%) | ¹⁶³Re | rowspan=3|11/2 | rowspan=3| | rowspan=3| |- | β⁺ (11%) | ¹⁶⁷Os |- | p (0.41%) | ¹⁶⁶Os |-id=Iridium-168 | ¹⁶⁸Ir |rowspan="4" style="text-align:right" | 91 | style="text-align:center;" | | | α | ¹⁶⁴Re | (2)- | | |-id=Iridium-168m | rowspan=3 style="text-indent:1em" | ^168mIr | rowspan=3 style="text-align:center;" | <br/> | rowspan=3| | α (77%) | ¹⁶⁴Re | rowspan=3|(9,10)+ | rowspan=3| | rowspan=3| |- | β⁺? | ¹⁶⁸Os |- | β⁺, p? | ¹⁶⁷Re |-id=Iridium-169 | rowspan=2|¹⁶⁹Ir | rowspan="5" style="text-align:right" | 92 | rowspan=2 style="text-align:center;" | | rowspan=2| | α (53%) | ¹⁶⁵Re | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | β⁺ (47%) | ¹⁶⁹Os |-id=Iridium-169m | rowspan=3 style="text-indent:1em" | ^169mIr | rowspan=3 style="text-align:center;" | <br/> | rowspan=3| | α (79%) | ¹⁶⁵Re | rowspan=3|(11/2) | rowspan=3| | rowspan=3| |- | β⁺? | ¹⁶⁹Os |- | p? | ¹⁶⁸Os |-id=Iridium-170 | rowspan=2|¹⁷⁰Ir | rowspan="5" style="text-align:right" | 93 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (94.8%) | ¹⁷⁰Os | rowspan=2|(3) | rowspan=2| | rowspan=2| |- | α (5.2%) | ¹⁶⁶Re |-id=Iridium-170m | rowspan=3 style="text-indent:1em" | ^170mIr | rowspan=3 style="text-align:center;" | <br/>40(50)#&nbsp;keV | rowspan=3| | α (38%) | ¹⁶⁶Re | rowspan=3|(8+) | rowspan=3| | rowspan=3| |- | β⁺? | ¹⁷⁰Os |- | IT? | ¹⁷⁰Ir |-id=Iridium-171 | rowspan=2|¹⁷¹Ir | rowspan="5" style="text-align:right" | 94 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (85%) | ¹⁷¹Os | rowspan=2|1/2+ | rowspan=2| | rowspan=2| |- | α (15%) | ¹⁶⁷Re |-id=Iridium-171m | rowspan=3 style="text-indent:1em" | ^171mIr | rowspan=3 style="text-align:center;" | <br/>164(11)#&nbsp;keV | rowspan=3| | α (54%) | ¹⁶⁷Re | rowspan=3|(11/2) | rowspan=3| | rowspan=3| |- | β⁺? | ¹⁷¹Os |- | p? | ¹⁷⁰Os |-id=Iridium-172 | rowspan=2|¹⁷²Ir | rowspan="4" style="text-align:right" | 95 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (~98%) | ¹⁷²Os | rowspan=2|(3,4) | rowspan=2| | rowspan=2| |- | α (~2%) | ¹⁶⁸Re |-id=Iridium-172m | rowspan=2 style="text-indent:1em" | ^172mIr | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | β⁺ (90.5%) | ¹⁷²Os | rowspan=2|(7+) | rowspan=2| | rowspan=2| |- | α (9.5%) | ¹⁶⁸Re |-id=Iridium-173 | rowspan=2|¹⁷³Ir | rowspan="4" style="text-align:right" | 96 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (96.5%) | ¹⁷³Os | rowspan=2|(1/2+,3/2+) | rowspan=2| | rowspan=2| |- | α (3.5%) | ¹⁶⁹Re |-id=Iridium-173m | rowspan=2 style="text-indent:1em" | ^173mIr | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | β⁺ (88%) | ¹⁷³Os | rowspan=2|11/2 | rowspan=2| | rowspan=2| |- | α (12%) | ¹⁶⁹Re |-id=Iridium-174 | rowspan=2|¹⁷⁴Ir | rowspan="4" style="text-align:right" | 97 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (99.5%) | ¹⁷⁴Os | rowspan=2|(2+,3) | rowspan=2| | rowspan=2| |- | α (0.5%) | ¹⁷⁰Re |-id=Iridium-174m | rowspan=2 style="text-indent:1em" | ^174mIr | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | β⁺ (97.5%) | ¹⁷⁴Os | rowspan=2|(6,7,8,9) | rowspan=2| | rowspan=2| |- | α (2.5%) | ¹⁷⁰Re |-id=Iridium-175 | rowspan=2|¹⁷⁵Ir | rowspan="4" style="text-align:right" | 98 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (99.15%) | ¹⁷⁵Os | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | α (0.85%) | ¹⁷¹Re |-id=Iridium-175m1 | style="text-indent:1em" | ^175m1Ir | style="text-align:center;" | <br/>50(40)#&nbsp;keV | | β⁺ | ¹⁷⁵Os | 9/2# | | |-id=Iridium-175m2 | style="text-indent:1em" | ^175m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁷⁵Ir | (5/2) | | |-id=Iridium-176 | rowspan=2|¹⁷⁶Ir | rowspan="2" style="text-align:right" | 99 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (96.9%) | ¹⁷⁶Os | rowspan=2|(3+) | rowspan=2| | rowspan=2| |- | α (3.1%) | ¹⁷²Re |-id=Iridium-177 | rowspan=2|¹⁷⁷Ir | rowspan="3" style="text-align:right" | 100 | rowspan=2 style="text-align:center;" | | rowspan=2| | β⁺ (99.94%) | ¹⁷⁷Os | rowspan=2|5/2 | rowspan=2| | rowspan=2| |- | α (0.06%) | ¹⁷³Re |-id=Iridium-177m | style="text-indent:1em" | ^177mIr | style="text-align:center;" | <br/> | | IT | ¹⁷⁷Ir | (5/2+) | | |-id=Iridium-178 | ¹⁷⁸Ir |rowspan="1" style="text-align:right" | 101 | style="text-align:center;" | | | β⁺ | ¹⁷⁸Os | 3+# | | |-id=Iridium-179 | ¹⁷⁹Ir |rowspan="1" style="text-align:right" | 102 | style="text-align:center;" | | | β⁺ | ¹⁷⁹Os | (5/2) | | |-id=Iridium-180 | ¹⁸⁰Ir |rowspan="1" style="text-align:right" | 103 | style="text-align:center;" | | | β⁺ | ¹⁸⁰Os | (5+) | | |-id=Iridium-181 | ¹⁸¹Ir |rowspan="3" style="text-align:right" | 104 | style="text-align:center;" | | | β⁺ | ¹⁸¹Os | 5/2 | | |-id=Iridium-181m1 | style="text-indent:1em" | ^181m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁸¹Ir | 5/2+ | | |-id=Iridium-181m2 | style="text-indent:1em" | ^181m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁸¹Ir | 9/2 | | |-id=Iridium-182 | ¹⁸²Ir |rowspan="3" style="text-align:right" | 105 | style="text-align:center;" | | | β⁺ | ¹⁸²Os | 3+ | | |-id=Iridium-182m1 | style="text-indent:1em" | ^182m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁸²Ir | (5)+ | | |-id=Iridium-182m2 | style="text-indent:1em" | ^182m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁸²Ir | (6) | | |-id=Iridium-183 | ¹⁸³Ir |rowspan="1" style="text-align:right" | 106 | style="text-align:center;" | | | β⁺ | ¹⁸³Os | 5/2 | | |-id=Iridium-184 | ¹⁸⁴Ir |rowspan="3" style="text-align:right" | 107 | style="text-align:center;" | | | β⁺ | ¹⁸⁴Os | 5 | | |-id=Iridium-184m1 | style="text-indent:1em" | ^184m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁴Ir | 3+ | | |-id=Iridium-184m2 | style="text-indent:1em" | ^184m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁴Ir | 7+ | | |-id=Iridium-185 | ¹⁸⁵Ir |rowspan="2" style="text-align:right" | 108 | style="text-align:center;" | | | β⁺ | ¹⁸⁵Os | 5/2 | | |-id=Iridium-185m | style="text-indent:1em" | ^185mIr | style="text-align:center;" | <br/> | | IT | ¹⁸⁵Ir | (23/2,25/2)# | | |-id=Iridium-186 | ¹⁸⁶Ir |rowspan="3" style="text-align:right" | 109 | style="text-align:center;" | | | β⁺ | ¹⁸⁶Os | 5+ | | |-id=Iridium-186m | rowspan=2 style="text-indent:1em" | ^186mIr | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | β⁺ (~75%) | ¹⁸⁶Os | rowspan=2|2 | rowspan=2| | rowspan=2| |- | IT (~25%) | ¹⁸⁶Ir |-id=Iridium-187 | ¹⁸⁷Ir |rowspan="4" style="text-align:right" | 110 | style="text-align:center;" | | | β⁺ | ¹⁸⁷Os | 3/2+ | | |-id=Iridium-187m1 | style="text-indent:1em" | ^187m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁷Ir | 9/2 | | |-id=Iridium-187m2 | style="text-indent:1em" | ^187m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁷Ir | 11/2 | | |-id=Iridium-187m3 | style="text-indent:1em" | ^187m3Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁷Ir | 29/2 | | |-id=Iridium-188 | ¹⁸⁸Ir |rowspan="2" style="text-align:right" | 111 | style="text-align:center;" | | | β⁺ | ¹⁸⁸Os | 1 | | |-id=Iridium-188m | style="text-indent:1em" | ^188mIr | style="text-align:center;" | <br/> | | IT | ¹⁸⁸Ir | 11# | | |-id=Iridium-189 | ¹⁸⁹Ir |rowspan="3" style="text-align:right" | 112 | style="text-align:center;" | | | EC | ¹⁸⁹Os | 3/2+ | | |-id=Iridium-189m1 | style="text-indent:1em" | ^189m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁹Ir | 11/2 | | |-id=Iridium-189m2 | style="text-indent:1em" | ^189m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁸⁹Ir | 25/2+ | | |-id=Iridium-190 | rowspan=2|¹⁹⁰Ir | rowspan="6" style="text-align:right" | 113 | rowspan=2 style="text-align:center;" | | rowspan=2| | EC | rowspan=2|¹⁹⁰Os | rowspan=2|4 | rowspan=2 | |- | β⁺ (<0.002%) |-id=Iridium-190m1 | style="text-indent:1em" | ^190m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁹⁰Ir | 1 | | |-id=Iridium-190m2 | style="text-indent:1em" | ^190m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁹⁰Ir | 4+ | | |-id=Iridium-190m3 | rowspan=2 style="text-indent:1em" | ^190m3Ir | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | EC (91.4%) | ¹⁹⁰Os | rowspan=2|11 | rowspan=2| | rowspan=2| |- | IT (8.6%) | ¹⁹⁰Ir |-id=Iridium-191 | ¹⁹¹Ir |rowspan="3" style="text-align:right" | 114 | style="text-align:center;" | | colspan=3 style="text-align:center;" data-sort-value=99999999999999999999999|Observationally Stable | 3/2+ | style="text-align:center;" | | |-id=Iridium-191m1 | style="text-indent:1em" | ^191m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁹¹Ir | 11/2 | | |-id=Iridium-191m2 | style="text-indent:1em" | ^191m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁹¹Ir | 31/2(+) | | |- | rowspan=2|¹⁹²Ir | rowspan=5 style="text-align:right" | 115 | rowspan=2 style="text-align:center;" | | rowspan=2| | β (95.24%) | ¹⁹²Pt | rowspan=2|4+ | rowspan=2| | rowspan=2| |- | EC (4.76%) | ¹⁹²Os |-id=Iridium-192m1 | rowspan=2 style="text-indent:1em" | ^192m1Ir | rowspan=2 style="text-align:center;" | <br/> | rowspan=2| | IT (99.98%) | ¹⁹²Ir | rowspan=2|1 | rowspan=2| | rowspan=2| |- | β (0.0175%) | ¹⁹²Pt |-id=Iridium-192m2 | style="text-indent:1em" | ^192m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁹²Ir | (11) | | |-id=Iridium-193 | ¹⁹³Ir |rowspan="3" style="text-align:right" | 116 | style="text-align:center;" | | colspan=3 style="text-align:center;" data-sort-value=99999999999999999999999|Observationally Stable | 3/2+ | style="text-align:center;" | | |-id=Iridium-193m1 | style="text-indent:1em" | ^193m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁹³Ir | 11/2 | | |-id=Iridium-193m2 | style="text-indent:1em" | ^193m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁹³Ir | 31/2+ | | |-id=Iridium-194 | ¹⁹⁴Ir |rowspan="3" style="text-align:right" | 117 | style="text-align:center;" | | | β | ¹⁹⁴Pt | 1 | | |-id=Iridium-194m1 | style="text-indent:1em" | ^194m1Ir | style="text-align:center;" | <br/> | | IT | ¹⁹⁴Ir | 4+ | | |-id=Iridium-194m2 | style="text-indent:1em" | ^194m2Ir | style="text-align:center;" | <br/> | | β | ¹⁹⁴Pt | (11) | | |-id=Iridium-195 | ¹⁹⁵Ir |rowspan="3" style="text-align:right" | 118 | style="text-align:center;" | | | β | ¹⁹⁵Pt | 3/2+ | | |-id=Iridium-195m1 | style="text-indent:1em" | ^195m1Ir | style="text-align:center;" | <br/> | | β | ¹⁹⁵Pt | 11/2 | | |-id=Iridium-195m2 | style="text-indent:1em" | ^195m2Ir | style="text-align:center;" | <br/> | | IT | ¹⁹⁵Ir | (27/2+) | | |-id=Iridium-196 | ¹⁹⁶Ir |rowspan="2" style="text-align:right" | 119 | style="text-align:center;" | | | β | ¹⁹⁶Pt | (1,2) | | |-id=Iridium-196m | style="text-indent:1em" | ^196mIr | style="text-align:center;" | <br/> | | β | ¹⁹⁶Pt | 11# | | |-id=Iridium-197 | ¹⁹⁷Ir |rowspan="4" style="text-align:right" | 120 | style="text-align:center;" | | | β | ¹⁹⁷Pt | 3/2+ | | |-id=Iridium-197m1 | style="text-indent:1em" | ^197m1Ir | style="text-align:center;" | <br/> | | β | ¹⁹⁷Pt | 11/2 | | |-id=Iridium-197m2 | style="text-indent:1em" | ^197m2Ir | style="text-align:center;" | <br/>1700(500)#&nbsp;keV | | IT | ¹⁹⁷Ir | | | |-id=Iridium-197m3 | style="text-indent:1em" | ^197m3Ir | style="text-align:center;" | <br/>2800(500)#&nbsp;keV | | IT | ¹⁹⁷Ir | | | |-id=Iridium-198 | ¹⁹⁸Ir |rowspan="1" style="text-align:right" | 121 | style="text-align:center;" | | | β | ¹⁹⁸Pt | 1 | | |-id=Iridium-199 | ¹⁹⁹Ir |rowspan="1" style="text-align:right" | 122 | style="text-align:center;" | | | β | ¹⁹⁹Pt | 3/2+# | | |-id=Iridium-200 | ²⁰⁰Ir |rowspan="1" style="text-align:right" | 123 | style="text-align:center;" | | | β | ²⁰⁰Pt | (2, 3) | | |-id=Iridium-201 | ²⁰¹Ir |rowspan="1" style="text-align:right" | 124 | style="text-align:center;" | | | β | ²⁰¹Pt | (3/2+) | | |-id=Iridium-202 | ²⁰²Ir |rowspan="2" style="text-align:right" | 125 | style="text-align:center;" | | | β | ²⁰²Pt | (2) | | |-id=Iridium-202m | style="text-indent:1em" | ^202mIr | style="text-align:center;" | <br/>2600(300)#&nbsp;keV | | IT | ²⁰²Ir | | | |-id=Iridium-203 | ²⁰³Ir |rowspan="2" style="text-align:right" | 126 | style="text-align:center;" | | [>300&nbsp;ns] | | | 3/2+# | | |-id=Iridium-203m | style="text-indent:1em" | ^203mIr | style="text-align:center;" | <br/>2140(50)#&nbsp;keV | | IT | ²⁰³Ir | | | |-id=Iridium-204 | ²⁰⁴Ir |rowspan="1" style="text-align:right" | 127 | style="text-align:center;" | | [>300&nbsp;ns] | | | 3/2+# | | |-id=Iridium-205 | ²⁰⁵Ir | style="text-align:right" | 128 | style="text-align:center;" | | [>300&nbsp;ns] | | | 3/2+# | |

Iridium-192

Iridium-192 (symbol ¹⁹²Ir) is a radioactive isotope of iridium, with a half-life of 73.82 days. It decays by emitting beta (β) particles and gamma (γ) radiation. 95.24% of ¹⁹²Ir decays occur via β^- emission, leading to ¹⁹²Pt; the remaining 4.76% occur via electron capture to ¹⁹²Os; both modes involve gamma emission. Iridium-192 is normally produced by neutron activation of natural-abundance iridium metal.

Iridium-192 is used in brachytherapy and in industrial radiography, particularly for nondestructive testing of welds in steel in the oil and gas industries.

See also

Daughter products other than iridium

• Isotopes of platinum
• Isotopes of osmium
• Isotopes of rhenium

References

External links

• NLM Hazardous Substances Databank &ndash; Iridium, Radioactive (referring to iridium-192)