147Sm

147Sm is an isotope of samarium. Samarium is a chemical element with the symbol Sm and atomic number 62. It is a rare earth element.

147Sm is a radioactive isotope with a long half-life of approximately 1.06 x 10^11 years. This means it decays very slowly. Its primary decay mode is alpha decay, where it transforms into 143Nd, an isotope of neodymium. Due to its long half-life, 147Sm is considered a primordial nuclide, meaning it has existed since the formation of the Earth.

The abundance of 147Sm in natural samarium is about 14.99%. The most abundant isotope of samarium is 152Sm. Samarium isotopes, including 147Sm, are found in trace amounts in the Earth's crust and are often associated with other rare earth elements.

In scientific research, 147Sm has been utilized as a source of alpha particles. Its slow decay rate and the energy of its emitted alpha particles make it suitable for certain calibration purposes in nuclear physics and for use in some specialized applications. The samarium-neodymium dating method, while primarily using other isotopes like 143Nd, relies on the decay chain originating from isotopes such as 147Sm. This technique is used in geochemistry and geology to determine the age of rocks and meteorites.