The switching characteristics of ferroelectrics and multiferroics are influenced by the interaction of topological defects with domain walls.We report on the pinning of polarization due to antiphase boundaries in thin...The switching characteristics of ferroelectrics and multiferroics are influenced by the interaction of topological defects with domain walls.We report on the pinning of polarization due to antiphase boundaries in thin films of the multiferroic hexagonal YbFeO_(3).We have directly resolved the atomic structure of a sharp antiphase boundary(APB)in YbFeO_(3) thin films using a combination of aberration-corrected scanning transmission electron microscopy(STEM)and total energy calculations based on density-functional theory(DFT).We find the presence of a layer of FeO_(6) octahedra at the APB that bridges the adjacent domains.STEM imaging shows a reversal in the direction of polarization on moving across the APB,which DFT calculations confirm is structural in nature as the polarization reversal reduces the distortion of the FeO_(6) octahedral layer at the APB.Such APBs in hexagonal perovskites are expected to serve as domain-wall pinning sites and hinder ferroelectric switching of the domains.展开更多
Magnetoelectric coupling has been a trending research topic in both organic and inorganic materials and hybrids.The concept of controlling magnetism using an electric field is particularly appealing in energy efficien...Magnetoelectric coupling has been a trending research topic in both organic and inorganic materials and hybrids.The concept of controlling magnetism using an electric field is particularly appealing in energy efficient applications.In this spirit,ferroelectricity has been introduced to organic spin valves to manipulate the magneto transport,where the spin transport through the ferromagnet/organic spacer interfaces(spinterface)are under intensive study.The ferroelectric materials in the organic spin valves provide a knob to vary the interfacial energy alignment and the interfacial crystal structures,both are critical for the spin transport.In this review,we introduce the recent efforts of controlling magnetoresistance of organic spin valves using ferroelectricity,where the ferroelectric material is either inserted as an interfacial layer or used as a spacer material.The realization of the ferroelectric control of magneto transport in organic spin valve,advances our understanding in the spin transport through the ferromagnet/organic interface,and suggests more functionality of organic spintronic devices.展开更多
基金supported by the National Science Foundation(NSF)(Grant Nos.DMR-2122070,2145797,and 1454618)by the Nebraska Center for Energy Sciences Research(NCESR)+3 种基金The Microscopy work was conducted as part of a user project at the Center for Nanophase Materials Sciences(CNMS)which is a US Department of Energy,Office of Science User Facility at Oak Ridge National LaboratoryThis work used computational resources through allocation DMR160007 from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)programwhich is supported by NSF grants#2138259,#2138286,#2138307,#2137603,and#2138296.
文摘The switching characteristics of ferroelectrics and multiferroics are influenced by the interaction of topological defects with domain walls.We report on the pinning of polarization due to antiphase boundaries in thin films of the multiferroic hexagonal YbFeO_(3).We have directly resolved the atomic structure of a sharp antiphase boundary(APB)in YbFeO_(3) thin films using a combination of aberration-corrected scanning transmission electron microscopy(STEM)and total energy calculations based on density-functional theory(DFT).We find the presence of a layer of FeO_(6) octahedra at the APB that bridges the adjacent domains.STEM imaging shows a reversal in the direction of polarization on moving across the APB,which DFT calculations confirm is structural in nature as the polarization reversal reduces the distortion of the FeO_(6) octahedral layer at the APB.Such APBs in hexagonal perovskites are expected to serve as domain-wall pinning sites and hinder ferroelectric switching of the domains.
基金This project was primarily supported by the National Science Foundation through the Nebraska Materials Research Science and Engineering Center(Grant No.DMR-1420645).
文摘Magnetoelectric coupling has been a trending research topic in both organic and inorganic materials and hybrids.The concept of controlling magnetism using an electric field is particularly appealing in energy efficient applications.In this spirit,ferroelectricity has been introduced to organic spin valves to manipulate the magneto transport,where the spin transport through the ferromagnet/organic spacer interfaces(spinterface)are under intensive study.The ferroelectric materials in the organic spin valves provide a knob to vary the interfacial energy alignment and the interfacial crystal structures,both are critical for the spin transport.In this review,we introduce the recent efforts of controlling magnetoresistance of organic spin valves using ferroelectricity,where the ferroelectric material is either inserted as an interfacial layer or used as a spacer material.The realization of the ferroelectric control of magneto transport in organic spin valve,advances our understanding in the spin transport through the ferromagnet/organic interface,and suggests more functionality of organic spintronic devices.
