First-principles study of the relaxor ferroelectricity of Ba(Zr,Ti)O${}_3$

Abstract

Ba(Zr,Ti)O${}_3$ is a lead-free relaxor ferroelectric. Using the first-principles method, the ferroelectric dipole moments for pure BaTiO${}_3$ and Ba(Zr,Ti)O${}_3$ supercells have been studied. All possible ion configurations of BaZr${}_{0.5}$Ti${}_{0.5}$O${}_3$ and BaZr${}_{0.25}$Ti${}_{0.75}$O${}_3$ are constructed in a $2\times 2\times 2$ supercell. For the half-substituted case, divergence of ferroelectric properties has been found among these structures, which seriously depends on the arrangement of Ti and Zr ions. Thus our results provide a reasonable explanation to the relaxor behavior of Ba(Zr,Ti)O${}_3$. In addition, a model based on the thermal statistics gives the averaged polarization for Ba(Zr,Ti)O${}_3$, which depends on the temperature of synthesis. Our result is helpful to understand and tune the relaxor ferroelectricity of lead-free Ba(Zr,Ti)O${}_3$.

15 pages, 2 figures, 2 tables

References in corpus (2)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces

Cited by in corpus (1)

• Giant Thermal Enhancement of the Electric Polarization in Ferrimagnetic BiFe${}_{1-x}$Co${}_x$O${}_3$ Solid Solutions Near Room Temperature