 The major commercial application of samarium is in samarium @-@ cobalt magnets , which have permanent magnetization second only to neodymium magnets ; however , samarium compounds can withstand significantly higher temperatures , above 700 ° C ( 1 @,@ 292 ° F ) , without losing their magnetic properties , due to the alloy 's higher Curie point . The radioactive isotope samarium @-@ 153 is the major component of the drug samarium ( 153Sm ) <unk> ( <unk> ) , which kills cancer cells in the treatment of lung cancer , prostate cancer , breast cancer and osteosarcoma . Another isotope , samarium @-@ 149 , is a strong neutron absorber and is therefore added to the control rods of nuclear reactors . It is also formed as a decay product during the reactor operation and is one of the important factors considered in the reactor design and operation . Other applications of samarium include catalysis of chemical reactions , radioactive dating and an X @-@ ray laser . 
