鏑（原子量：162500 1）的同位素中有 7 個是存在於自然界的穩定同位素，分別是 156Dy、158Dy 和 160Dy 至 164Dy。自然同位素中豐度最高的是比例為 28 的 164Dy，緊接著的是比例為 26 的 162Dy。豐度最低的是比例為 006 的 156Dy。 透過人工合成，科學家共發現了 29 種放射性同位素，其原子量在 138 和 173 之間。最穩定的是 154Dy，其半衰期約為 140 年；接著是半衰期為 1444 天的 159Dy。最不穩定的是 138Dy，其半衰期只有 200 毫秒。比穩定同位素輕的同位素主要進行 β 衰變；除個別特例之外，更重的同位素主要進行 β衰變。154Dy 主要進行 α 衰變，152Dy 和 159Dy 則主要進行電子捕獲。鏑擁有至少 11 種同核異構體（亞穩態），原子量在 140 和 165 之間。最穩定的是 165mDy，其半衰期為 1257 分鐘。149Dy 有兩種亞穩態，第二種（149m2Dy）的半衰期只有 28 納秒。 164Dy 是理論上最重的穩定同位素，任何更重的同位素，理論上都會進行 α 衰變，但是在鉛 208 以下，絕大部分的同位素都尚未觀測到此衰變。 圖表 138Dy styletextalignright 66 styletextalignright 72 13796249 64 200 ms 0 139Dy styletextalignright 66 styletextalignright 73 13895954 54 600 200 ms 72 140Dy styletextalignright 66 styletextalignright 74 13995401 54 700 ms 140Tb 0 styletextindent1em 140mDy colspan3 styletextindent2em 21661 5 keV 70 5 µs 8 rowspan2141Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 75 rowspan214095135 32 rowspan209 2 s 141Tb rowspan292 rowspan2 rowspan2 （不常見） 140Gd rowspan2142Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 76 rowspan214194637 39 rowspan223 3 s 9994 142Tb rowspan20 rowspan2 rowspan2 06 141Gd rowspan2143Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 77 rowspan214294383 21 rowspan256 10 s 143Tb rowspan212 rowspan2 rowspan2 （不常見） 142Gd styletextindent1em 143mDy colspan3 styletextindent2em 3107 6 keV 30 3 s 112 rowspan2144Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 78 rowspan214393925 3 rowspan291 4 s 144Tb rowspan20 rowspan2 rowspan2 （不常見） 143Gd rowspan2145Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 79 rowspan214493743 5 rowspan295 10 s 145Tb rowspan212 rowspan2 rowspan2 （不常見） 144Gd styletextindent1em 145mDy colspan3 styletextindent2em 1182 2 keV 141 7 s 145Tb 112 146Dy styletextalignright 66 styletextalignright 80 145932845 29 332 7 s 146Tb 0 styletextindent1em 146mDy colspan3 styletextindent2em 29357 6 keV 150 20 ms IT 146Dy 10 rowspan2147Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 81 rowspan2146931092 21 rowspan240 10 s 9995 147Tb rowspan212 rowspan2 rowspan2 05 146Tb rowspan2 styletextindent1em 147m1Dy rowspan2 colspan3 styletextindent2em 7505 4 keV rowspan255 1 s 65 147Tb rowspan2112 rowspan2 rowspan2 IT 35 147Dy styletextindent1em 147m2Dy colspan3 styletextindent2em 34072 8 keV 040 1 µs 272 148Dy styletextalignright 66 styletextalignright 82 147927150 11 33 2 min 148Tb 0 149Dy styletextalignright 66 styletextalignright 83 148927305 9 420 14 min 149Tb 72 rowspan2 styletextindent1em 149mDy rowspan2 colspan3 styletextindent2em 26611 4 keV rowspan2490 15 ms IT 993 149Dy rowspan2272 rowspan2 rowspan2 7 149Tb rowspan2150Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 84 rowspan2149925585 5 rowspan2717 5 min 64 150Tb rowspan20 rowspan2 rowspan2 36 146Gd rowspan2151Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 85 rowspan2150926185 4 rowspan2179 3 min 944 151Tb rowspan272 rowspan2 rowspan2 56 147Gd rowspan2152Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 86 rowspan2151924718 6 rowspan2238 2 h 999 152Tb rowspan20 rowspan2 rowspan2 1 148Gd rowspan2153Dy rowspan2 styletextalignright 66 rowspan2 styletextalignright 87 rowspan2152925765 5 rowspan264 1 h 9999 153Tb rowspan272 rowspan2 rowspan2 00939 149Gd 154Dy styletextalignright 66 styletextalignright 88 153924424 8 30 15106 a 150Gd 0 155Dy styletextalignright 66 styletextalignright 89 154925754 13 99 2 h 155Tb 32 styletextindent1em 155mDy colspan3 styletextindent2em 23433 3 keV 6 1 µs 112 156Dy styletextalignright 66 styletextalignright 90 155924283 7 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 152Gd or decay to 156Gd with a halflife over 1018 years 0 56 3104 157Dy styletextalignright 66 styletextalignright 91 156925466 7 814 4 h 157Tb 32 styletextindent1em 157m1Dy colspan3 styletextindent2em 16199 3 keV 13 2 µs 92 styletextindent1em 157m2Dy colspan3 styletextindent2em 19938 7 keV 216 16 ms IT 157Dy 112 158Dy styletextalignright 66 styletextalignright 92 157924409 4 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 154Gd or decay to 158Gd 0 95 3104 159Dy styletextalignright 66 styletextalignright 93 1589257392 29 1444 2 d 159Tb 32 styletextindent1em 159mDy colspan3 styletextindent2em 35277 14 keV 122 3 µs 112 160Dy styletextalignright 66 styletextalignright 94 1599251975 27 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 156Gd 0 002329 18 161Dy styletextalignright 66 styletextalignright 95 1609269334 27 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 157Gd 52 018889 42 162Dy styletextalignright 66 styletextalignright 96 1619267984 27 colspan3 aligncenter 觀測上穩定 Believed to undergo decay to 158Gd 0 025475 36 163Dy styletextalignright 66 styletextalignright 97 1629287312 27 colspan3 aligncenterCan undergo boundstate decay to 163Ho with a halflife of 47 days when fully ionizedM Jung et al Phys Rev Letts 69 2164 1992 First observation of boundstate beta minus decay 52 024896 42 164Dy styletextalignright 66 styletextalignright 98 1639291748 27 colspan3 aligncenter 0 028260 54 165Dy styletextalignright 66 styletextalignright 99 1649317033 27 2334 1 h 165Ho 72 rowspan2 styletextindent1em 165mDy rowspan2 colspan3 styletextindent2em 108160 3 keV rowspan21257 6 min IT 9776 165Dy rowspan212 rowspan2 rowspan2 224 165Ho 166Dy styletextalignright 66 styletextalignright 100 1659328067 28 816 1 h 166Ho 0 167Dy styletextalignright 66 styletextalignright 101 16693566 6 620 8 min 167Ho 12 168Dy styletextalignright 66 styletextalignright 102 16793713 15 87 3 min 168Ho 0 169Dy styletextalignright 66 styletextalignright 103 16894031 32 39 8 s 169Ho 52 170Dy styletextalignright 66 styletextalignright 104 16994239 21 30 s 170Ho 0 171Dy styletextalignright 66 styletextalignright 105 17094620 32 6 s 171Ho 72 172Dy styletextalignright 66 styletextalignright 106 17194876 43 3 s 172Ho 0 173Dy styletextalignright 66 styletextalignright 107 17295300 54 2 s 173Ho 92 參考文獻 Isotope masses from Ame2003 Atomic Mass Evaluation by G Audi AH Wapstra C Thibault J Blachot and O Bersillon in Nuclear Physics A729 2003 Isotopic compositions and standard atomic masses from Atomic weights of the elements Review 2000 IUPAC Technical Report Pure Appl Chem Vol 75 No 6 pp 683800 2003 and Atomic Weights Revised 2005 Halflife spin and isomer data selected from these sources Editing notes on this articles talk page Audi Bersillon Blachot Wapstra The Nubase2003 evaluation of nuclear and decay properties Nuc Phys A 729 pp 3128 2003 National Nuclear Data Center Brookhaven National Laboratory Information extracted from the NuDat 21 database retrieved Sept 2005 David R Lide ed Norman E Holden in CRC Handbook of Chemistry and Physics 85th Edition online version CRC Press Boca Raton Florida 2005 Section 11 Table of the Isotopes Dy Category 鏑