Effect of pressure on the Raman modes in LiNbO(3) and LiTaO (3).
01 January 1986
The pressure dependence of the optical phonons in LiNbO(3) to 21 GPa and in LiTaO(3) to 10 GPa has been investigated by Raman spectroscopy, using the diamond anvil cell. All the observed modes increase in frequency with pressure and no mode softening occurs. This is in contrast with the behavior observed in BaTiO(3) and PbtiO(3) which are well known displacive type ferroelectric. It is suggested that this difference in pressure behavior may stem from a different type of phase transition in LiNbO(3) and LiTaO(3), namely the order-disorder type.