Phonon Spectrum and Elastic Properties of Y2Sn2O7

摘要

The phonon spectrum of yttrium stannate Y2Sn2O7 is calculated within a general ab initio approach and the frequencies and types of IR and Raman modes are determined. The degree of involvement of ions in phonon modes is determined from the analysis of displacement vectors calculated ab initio. The elastic constants and hardness of Y2Sn2O7 are calculated. The impurity ion-ligand distance in Y2Sn2O7:Yb3+, Y2Sn2O7:Eu3+, Lu2Sn2O7:Yb3+, Nd2Sn2O7:Gd3+, and Nd2Sn2O7:Tb3+ impurity centers is calculated.