A lattice dynamical investigation of the Raman and the infrared frequencies of the cubic A2Hf2O7 pyrochlores

A short range force constant model has been applied for the first time to investigate the Raman and the infrared frequencies in A2Hf2O7 (A=La, Nd, Sm, Eu) pyrochlores in their cubic phase of space group . The calculations of zone center phonons have been made with five stretching and two bending force constants. The calculated values of Raman and infrared frequencies are in good agreement with the observed ones.