Ferroelectric phase transition in LiNbO3: Insights from molecular dynamics

Ab initio molecular dynamics within density functional theory is used for the first time to model the ferroelectric-paraelectric phase transition in LiNbO
₃
. Our calculations show that the structural phase transition is not an abrupt event, but rather a continuous process occurring over a range of about 100K and involving different ionic species at different temperatures. Because of the different behavior of the Li and Nb sublattices, the ferroelectric transition displays both displacive and order-disorder character.