A CORRELATION BETWEEN THE FERROELECTRIC PHASE TRANSITION AND THE CELL VOLUME IN BARIUM STRONTIUM TITANATE

The T C of Ba μ Sr 1-μ TiO 3 (BST) as a f unction of the composition and the lattice parameter γ is examined. It is compa red with the lattice parameter dependence of T C of BaTiO 3 and SrTiO 3 respectively. It is argued that the variation of T C in BST can be attributed to the change of cell volume. The order and the di ffuseness of the phase transition are also discussed from the volume effect view point. The fact that the Ba and Sr are ionized leads to the volume effect of BST .