Abstract How different microscopic mechanisms of ultrafast spin dynamics coexist and interplay is not only relevant for the development of spintronics but also for the thorough description of physical systems out-of-equilibrium. In pure crystalline ferromagnets. one of the main microscopic mechanism of spin relaxation is the electron-phonon (el-ph) driven spin-flip. or Elliott-Yafet. https://www.bempresas.com/