Phase transition in CdHfO3

Convert Widespread Paraelectric Perovskite to Ferroelectrics

“…We validate the design rule in a prototypical perovskite CdHfO 3 [29,30] by an effective Hamiltonian approach built upon the first-principles calculations, in which the epitaxial strains and electric displacement fields are considered as tunable parameters in experiments. We find that the improper mechanisms underlying the antiferroelectric (AFE) in CTO-type perovskites [29,31,32] and FE in BFO-type perovskites have distinct dependences on its mechanical and electric boundary conditions. With the increased applied tensile strain, the AFE ordering via the trilinear coupling [12,13] in CTO-type structure becomes destabilized much more rapidly than the FE ordering via four-linear coupling in a BFO-type structure [19,33].…”

“…This approach is based on proper choices of mechanical and electric boundary conditions via modern thin-film technology [27,28]. We validate the design rule in a prototypical perovskite CdHfO 3 [29,30] by an effective Hamiltonian approach built upon the first-principles calculations, in which the epitaxial strains and electric displacement fields are considered as tunable parameters in experiments. We find that the improper mechanisms underlying the antiferroelectric (AFE) in CTO-type perovskites [29,31,32] and FE in BFO-type perovskites have distinct dependences on its mechanical and electric boundary conditions.…”

“…( 1) and ( 2), the coefficients of the energy terms such as aðfη i gÞ and bðfη i gÞ are strain dependent; detailed expressions are shown in the Supplemental Material [40], which includes Refs. [29,[41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. We further group all the energy terms into subcategories according to their physical effects.…”

Convert widespread paraelectric perovskite to ferroelectrics

“…We validate the design rule in a prototypical perovskite CdHfO 3 [29,30] by an effective Hamiltonian approach built upon the first-principles calculations, in which the epitaxial strains and electric displacement fields are considered as tunable parameters in experiments. We find that the improper mechanisms underlying the antiferroelectric (AFE) in CTO-type perovskites [29,31,32] and FE in BFO-type perovskites have distinct dependences on its mechanical and electric boundary conditions. With the increased applied tensile strain, the AFE ordering via the trilinear coupling [12,13] in CTO-type structure becomes destabilized much rapidly than the FE ordering via four-linear coupling in BFO-type structure [19,33].…”