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

Abstract

Abstract Infrared absorption and polarized Raman spectra of rare‐earth titanates of pyrochlore structure Ln 2 Ti 2 O 7 (Ln = Sm, Gd, Yb; Y) and Ln 2 Sn 2 O 7 (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.