THE EFFECT OF NEAREST NEIGHBOR [Pb─O] DIVACANCY PAIRS ON THE FERROELECTRIC-RELAXOR TRANSITION IN NANO-ORDERED Pb(Sc1/2Nb1/2)O3
Abstract:Molecular dynamics simulations were performed on a first-principles-based effective Hamiltonians for chemically short-range ordered Pb(Sc1/2Nb1/2) O3 with nearest neighbor [Pb─O] divacancy pairs. The divacancy-concentration (X[Pb-O]) vs. temperature phase diagram was calculated, and it is topologically equivalent to the hydrostatic pressure (P) vs. temperature diagram: a ferroelectric ground-state phase at low X[Pb - O] (P); that transforms to a relaxor paraelectric phase at moderate X[Pb - O] (P); followed by a crossover to a normal paraelectric phase at high X[Pb - O](P).
Document Type: Research Article
Affiliations: 1: Ceramics Division, Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA 2: J. Nehru Theoretical Sciences Unit, JNCASR, Jakkur, Bangalore, India
Publication date: 2008-01-01