A new look at the temperature-dependent properties of the antiferroelectric model PbZrO3: an effective Hamiltonian study
arXiv:2211.04679 · doi:10.1103/PhysRevB.106.214108
Abstract
A novel atomistic effective Hamiltonian scheme, incorporating an original and simple bilinear energetic coupling, is developed and used to investigate the temperature dependent physical properties of the prototype antiferroelectric PbZrO3 (PZO) system. This scheme reproduces very well the known experimental hallmarks of the complex Pbam orthorhombic phase at low temperatures and the cubic paraelectric state of Pm 3m symmetry at high temperatures. Unexpectedly, it further predicts a novel intermediate state also of Pbam symmetry, but in which anti-phase oxygen octahedral tiltings have vanished with respect to the Pbam ground state. Interestingly, such new state exhibits a large dielectric response and thermal expansion that remarkably agree with previous experimental observations and the x-ray experiments we performed. We also conducted direct first-principles calculations at 0K which further support such low energy phase. Within this fresh framework, a re-examination of the properties of PZO is thus called for.
21 pages, 4 figures. This paper is submitted to Physical Review B
References in corpus (7)
- Restoring the density-gradient expansion for exchange in solids and surfaces
- Generalized gradient approximation for solids and their surfaces
- Phase diagram of Pb(Zr,Ti)O3 solid solutions from first principles
- First-principles study of the multi-mode anti-ferroelectric transition of PbZrO3
- Uncompensated Polarization in Incommensurate Modulations of Perovskite Antiferroelectrics
- Order-disorder transition in the prototypical antiferroelectric PbZrO
- A re-examination of antiferroelectric PbZrO and PbHfO: an 80-atom structure