Microstructural Study of the Li⁺Ion Substituted Perovskites Li_0.5-3xNd_0.5+xTiO₃

The microstructure of samples of different polymorphs belonging to the cation-deficient Li_0.5-3xNd_0.5+xTiO₃0.016<x<0.12 solid solution has been studied by ED and TEM. The basic cell of all of them is a diagonal perovskite with dimensions~2a_p~2a_p~2a_p. However, important differences between the polymorphs have been found in the microstructure. While inC-phase samples a randomly oriented microdomain structure of the basic cell is found, for the β polymorph materials a more complex domain microstructure gives rise to a very large superperiodicity (a=58.6 Åb=90.7 Å) as is also the case for the α′ polymorph samples.