The structural ordering characteristics of lead magnesium niobate (PMN) and solid solutions (PMN-PT) of PMN with lead titanate have been investigated using transmission electron microscopy (TEM). It is proposed that short range, non-stoichiometric 1:1 ordering of the Mg and Nb cations on an F-centred superlattice generates space charges which dominate the kinetics of the ordering process and inhibit the development of long-range order. Furthermore, it is demonstrated that by introducing off-valent La3+ ions on to the A-site sublattice, the local charges can be at least partially-compensated and an increase in the extent of structural ordering is consequently observed.
All Science Journal Classification (ASJC) codes
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering