Title :
Ferroelectric phase transition in LiNbO3: Insights from molecular dynamics
Author :
Sanna, Simone ; Schmidt, Wolf Gero
Author_Institution :
Lehrstuhl fur Theorethische Phys., Univ. Paderborn, Paderborn, Germany
fDate :
9/1/2012 12:00:00 AM
Abstract :
Ab initio molecular dynamics within density functional theory is used for the first time to model the ferroelectric-paraelectric phase transition in LiNbO3. 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.
Keywords :
ab initio calculations; density functional theory; displacive transformations; ferroelectric Curie temperature; ferroelectric transitions; lithium compounds; molecular dynamics method; order-disorder transformations; Curie temperature; LiNbO3; ab initio calculation; density functional theory; displacive transformation; ferroelectric-paraelectric phase transition; ionic species; molecular dynamics method; order-disorder transition; structural phase transition; Crystals; Ions; Lithium niobate; Optical scattering; Temperature distribution; Temperature measurement;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2012.2408
