When a g-quantum is emitted by a nucleus located in a crystal lattice, the recoil energy is converted into excitation of phonons, i.e. a set of oscillators corresponding to the natural vibrations of the crystal. According to quantum mechanics, there is a finite probability f for oscillators to remain in an unexcited state, and this process corresponds to radiation without recoil (the Mössbauer effect), which is defined by the expression f = exp(-4n2(x2)/l), where (x2) is the root-mean-square displacement of the nuclei during thermal fluctuations

Answer. Format gif