Lead zirconate(PbZrO_(3))is considered the prototypical antiferroelectric material with an antipolar ground state.Yet,several experimental and theoretical works hint at a partially polar behaviour in this compound,ind...Lead zirconate(PbZrO_(3))is considered the prototypical antiferroelectric material with an antipolar ground state.Yet,several experimental and theoretical works hint at a partially polar behaviour in this compound,indicating that the polarization may not be completely compensated.In this work,we propose a simple ferrielectric structure for lead zirconate.First-principles calculations reveal this state to be more stable than the commonly accepted antiferroelectric phase at low temperatures,possibly up to room temperature,suggesting that PbZrO_(3)may not be antiferroelectric at ambient conditions.We discuss the implications of our discovery,how it can be reconciled with experimental observations and how the ferrielectric phase could be obtained in practice.展开更多
Perovskite oxides offer tremendous potential for applications in information storage and energy conversion,owing to a subtle interplay between their spin,charge,orbital and lattice degrees of freedom.Here,we further e...Perovskite oxides offer tremendous potential for applications in information storage and energy conversion,owing to a subtle interplay between their spin,charge,orbital and lattice degrees of freedom.Here,we further expand the possible range of perovskite oxides operation towards the fields of thermal management and thermal computing by exploiting an exceptional synergy between different ferroic orders.We propose dynamical control of the heat flow in a distinctive family of perovskite oxides obtained via the application of small electric(~10 kV/cm)and/or magnetic(~1 T)fields.Based on first-principles simulations,we predict a relative heat conductivity variation of~100%in SrMnO_(3) thin films near room temperature resulting from a phase transition that involves huge changes in both the magnetization and electric polarization.The disclosed giant multiphononic effects are fundamentally caused by anharmonic spin-phonon couplings that strongly influence the mean lifetime of phonons.展开更多
基金H.A.and J.Í.acknowledge funding by the Luxembourg National Research Fund through the project INTER/ANR/16/11562984/EXPAND/KreiselC.C.acknowledges support from the Spanish Ministry of Science,Innovation and Universities under the“Ramón y Cajal”fellowship RYC2018-024947-1+3 种基金I.M.S.acknowledges the support of Ministerio de Economía,Industria y Competitividad(MINECO-Spain)through Grant No.PID2019-108573GB-C22Severo Ochoa FUNFUTURE centre of excellence(CEX2019-000917-S)of Generalitat de Catalunya(Grant No.2017 SGR1506)of the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant Agreement No.724529).
文摘Lead zirconate(PbZrO_(3))is considered the prototypical antiferroelectric material with an antipolar ground state.Yet,several experimental and theoretical works hint at a partially polar behaviour in this compound,indicating that the polarization may not be completely compensated.In this work,we propose a simple ferrielectric structure for lead zirconate.First-principles calculations reveal this state to be more stable than the commonly accepted antiferroelectric phase at low temperatures,possibly up to room temperature,suggesting that PbZrO_(3)may not be antiferroelectric at ambient conditions.We discuss the implications of our discovery,how it can be reconciled with experimental observations and how the ferrielectric phase could be obtained in practice.
基金We acknowledge financial support by MCIN/AEI/10.13039/501100011033 under grant PID2020-119777GB-I00the Ramón y Cajal fellowship RYC2018-024947-I+2 种基金the Severo Ochoa Centres of Excellence Program(CEX2019-000917-S)the Generalitat de Catalunya under grant no.and 2017 SGR 1506Calculations were performed at the Centro de Supercomputación de Galicia(CESGA)within action FI-2022-1-0012 of the Red Española de Supercomputación(RES).We also thank the support of the Luxembourg National Research Fund through project FNR/C18/MS/12705883/REFOX(J.Í.).
文摘Perovskite oxides offer tremendous potential for applications in information storage and energy conversion,owing to a subtle interplay between their spin,charge,orbital and lattice degrees of freedom.Here,we further expand the possible range of perovskite oxides operation towards the fields of thermal management and thermal computing by exploiting an exceptional synergy between different ferroic orders.We propose dynamical control of the heat flow in a distinctive family of perovskite oxides obtained via the application of small electric(~10 kV/cm)and/or magnetic(~1 T)fields.Based on first-principles simulations,we predict a relative heat conductivity variation of~100%in SrMnO_(3) thin films near room temperature resulting from a phase transition that involves huge changes in both the magnetization and electric polarization.The disclosed giant multiphononic effects are fundamentally caused by anharmonic spin-phonon couplings that strongly influence the mean lifetime of phonons.
