title: Origin of the relaxor state in Pb(B{x}B{1-x}{'})O(3) perovskites.
abstract: Molecular dynamics simulations of first-principles-based effective Hamiltonians for Pb(Sc{1/2}Nb{1/2})O(3) under hydrostatic pressure and for Pb(Mg{1/3}Nb{2/3})O(3) at ambient pressure show clear evidence of a relaxor state in both systems. The Burns temperature is identified as the temperature below which dynamic nanoscale polar clusters form, pinned to regions of quenched chemical short-range order. The effect of pressure in Pb(Sc{1/2}Nb{1/2})O(3) demonstrates that the stability of the relaxor state depends on a delicate balance between the energetics that stabilize normal ferroelectricity and the average strength of random local fields which promote the relaxor state.
authors.affiliation: Ceramics Division, Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8520, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Tinte
authors.forename: B P
authors.initials: BP
authors.lastname: Burton
authors.forename: Eric
authors.initials: E
authors.lastname: Cockayne
authors.forename: U V
authors.initials: UV
authors.lastname: Waghmare