Rare‐earth titanates and stannates of pyrochlore structure; vibrational spectra and force fields

Abstract
Infrared absorption and polarized Raman spectra of rare‐earth titanates of pyrochlore structure Ln2Ti2O7 (Ln = Sm, Gd, Yb; Y) and Ln2Sn2O7 (Ln = La, Sm, Gd, Yb, Lu; Y) have been recorded. A valence force field calculation clearly supports the assignment of the frequencies. A comparison of the results with those of homologous zirconates and hafnates is presented.