MICROSTRUCTURAL STUDY OF THE LI-3XND0.5+XTIO3( ION SUBSTITUTED PEROVSKITES LI0.5)

The microstructure of samples of different polymorphs belonging to the cation-deficient Li0.5-3xNd0.5+xTiO3 0.016 < x < 0.12 solid solution has been studied by ED and TEM. The basic cell of all of them is a dia gonal perovskite with dimensions similar to root 2(p) similar to root 2a(p) similar to 2a(p). However, important differences between the pol ymorphs have been found in the microstructure. While in C-phase sample s a randomly oriented microdomain structure of the basic cell is found , for the beta polymorph materials a more complex domain microstructur e gives rise to a very large superperiodicity (a = 58.6 Angstrom b = 9 0.7 Angstrom) as is also the case for the alpha' polymorph samples. (C ) 1997 Academic Press.