Finite temperature properties of ferroelectric halide perovskites
Abstract
Halide perovskites are known for their optoelectronic properties. Recent experimental demonstrations of ferroelectricity in CsGeX3 and the following theoretical proposition of polar and antipolar phases in CsGeBr3 have gained renewed interest in Ge-based perovskites. Using the first-principle-based methods, we parameterize the effective Hamiltonian for CsGeCl3 and CsGeI3 to examine phases and the type of phase transition across the temperature. Across all three materials, our approach anticipates a transition from the cubic (Pm3m) to the rhombohedral (R3m) phase. In addition, we observe the dynamical nature of local modes beyond the Curie temperature. The quenching from temperatures above TC to the lower temperature stabilize the dynamical phases and host order, as well as irregular dipole patterns, consisting of polar and antipolar regions, making CsGeX3 an ace material for practical applications.
Home Country
India
College
College of Arts and Sciences
Specialization
Physics
Faculty Sponsor
Inna Ponomareva
Poster
Presentation Type
Event
Finite temperature properties of ferroelectric halide perovskites
Halide perovskites are known for their optoelectronic properties. Recent experimental demonstrations of ferroelectricity in CsGeX3 and the following theoretical proposition of polar and antipolar phases in CsGeBr3 have gained renewed interest in Ge-based perovskites. Using the first-principle-based methods, we parameterize the effective Hamiltonian for CsGeCl3 and CsGeI3 to examine phases and the type of phase transition across the temperature. Across all three materials, our approach anticipates a transition from the cubic (Pm3m) to the rhombohedral (R3m) phase. In addition, we observe the dynamical nature of local modes beyond the Curie temperature. The quenching from temperatures above TC to the lower temperature stabilize the dynamical phases and host order, as well as irregular dipole patterns, consisting of polar and antipolar regions, making CsGeX3 an ace material for practical applications.
