Oxide-metal based nanocomposite thin films have attracted great interests owing to their unique anisotropic structure and physical properties.A wide range of Au-based oxide-metal nanocomposites have been demonstrated,...Oxide-metal based nanocomposite thin films have attracted great interests owing to their unique anisotropic structure and physical properties.A wide range of Au-based oxide-metal nanocomposites have been demonstrated,while other metal systems are scarce due to the challenges in the initial nucleation and growth as well as possible interdiffusions of the metallic nanopillars.In this work,a unique anodic aluminum oxide(AAO)template was used to grow a thin Co seed layer and the following self-assembled metal-oxide(Co-BaTiO_(3))vertically aligned nanocomposite thin film layer.The AAO template allows the uniform growth of Co-seeds and successfully deposition of highly ordered Co pillars(with diameter<5 nm and interval between pillars<10 nm)inside the oxide matrix.Significant magnetic anisotropy and strong magneto-optical coupling properties have been observed.A thin Au-BaTiO_(3) template was also later introduced for further enhanced nucleation and ordered growth of the Co-nanopillars.Taking the advantage of such a unique nanostructure,a large out-of-plane(OP)coercive field(Hc)of~5000 Oe has been achieved,making the nanocomposite an ideal candidate for high density perpendicular magnetic tunneling junction(p-MTJ).A strong polar magneto-optical Kerr effect(MOKE)has also been observed which inspires a novel optical-based reading method of the MTJ states.展开更多
Two-dimensional(2D)layered oxides have recently attracted wide attention owing to the strong coupling among charges,spins,lattice,and strain,which allows great flexibility and opportunities in structure designs as wel...Two-dimensional(2D)layered oxides have recently attracted wide attention owing to the strong coupling among charges,spins,lattice,and strain,which allows great flexibility and opportunities in structure designs as well as multifunctionality exploration.In parallel,plasmonic hybrid nanostructures exhibit exotic localized surface plasmon resonance(LSPR)providing a broad range of applications in nanophotonic devices and sensors.A hybrid material platform combining the unique multifunctional 2D layered oxides and plasmonic nanostructures brings optical tuning into the new level.In this work,a novel self-assembled Bi2MoO6(BMO)2D layered oxide incorporated with plasmonic Au nanoinclusions has been demonstrated via one-step pulsed laser deposition(PLD)technique.Comprehensive microstructural characterizations,including scanning transmission electron microscopy(STEM),differential phase contrast imaging(DPC),and STEM tomography,have demonstrated the high epitaxial quality and particle-in-matrix morphology of the BMO-Au nanocomposite film.DPC-STEM imaging clarifies the magnetic domain structures of BMO matrix.Three different BMO structures including layered supercell(LSC)and superlattices have been revealed which is attributed to the variable strain states throughout the BMO-Au film.Owing to the combination of plasmonic Au and layered structure of BMO,the nanocomposite film exhibits a typical LSPR in visible wavelength region and strong anisotropy in terms of its optical and ferromagnetic properties.This study opens a new avenue for developing novel 2D layered complex oxides incorporated with plasmonic metal or semiconductor phases showing great potential for applications in multifunctional nanoelectronics devices.展开更多
Multiferroics are an intriguing family of materials due to the simultaneous presence of two ferroic orderings,namely,ferroelectricity and ferromagnetism.They are scientifically and technologically important and have n...Multiferroics are an intriguing family of materials due to the simultaneous presence of two ferroic orderings,namely,ferroelectricity and ferromagnetism.They are scientifically and technologically important and have numerous potential applications,such as four-state logic memories and multiferroic tunneling junctions.However,the growth of epitaxial singlephase multiferroic thin films typically requires single crystalline oxide substrates,which hinders their future integration with Sibased devices.In this study,we report a generalized synthesis method that uses the polydimethylsiloxane(PDMS)-assisted wetetching method with an Sr_(3)Al_(2)O_(6)(SAO)sacrificial layer to transfer freestanding single-phase multiferroic Bi_(2)NiMnO_(6)(BNMO)films from conventional SrTiO_(3)(STO)substrates onto a Si wafer.The structures and properties of the films have been characterized before and after the transfer.These transferred films possess good multiferroic properties on Si wafers,indicating full compatibility with modern Si technology.This method can be generally applicable to other Bi-based multiferroic materials as well.Lastly,the original STO substrates after the transfer process have been recycled for preparing new batches of freestanding BNMO films,indicating a low-cost and sustainable method for manufacturing large-volume freestanding complex oxide thin films.展开更多
基金funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences with award No.DE-SC0020077.
文摘Oxide-metal based nanocomposite thin films have attracted great interests owing to their unique anisotropic structure and physical properties.A wide range of Au-based oxide-metal nanocomposites have been demonstrated,while other metal systems are scarce due to the challenges in the initial nucleation and growth as well as possible interdiffusions of the metallic nanopillars.In this work,a unique anodic aluminum oxide(AAO)template was used to grow a thin Co seed layer and the following self-assembled metal-oxide(Co-BaTiO_(3))vertically aligned nanocomposite thin film layer.The AAO template allows the uniform growth of Co-seeds and successfully deposition of highly ordered Co pillars(with diameter<5 nm and interval between pillars<10 nm)inside the oxide matrix.Significant magnetic anisotropy and strong magneto-optical coupling properties have been observed.A thin Au-BaTiO_(3) template was also later introduced for further enhanced nucleation and ordered growth of the Co-nanopillars.Taking the advantage of such a unique nanostructure,a large out-of-plane(OP)coercive field(Hc)of~5000 Oe has been achieved,making the nanocomposite an ideal candidate for high density perpendicular magnetic tunneling junction(p-MTJ).A strong polar magneto-optical Kerr effect(MOKE)has also been observed which inspires a novel optical-based reading method of the MTJ states.
基金This work was supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences(BES)under Award DESC0020077.D.Z.,J.S.,Z.S.,and H.W.acknowledge the support from the U.S.Office of Naval Research under contract Nos.N00014-20-1-2043 for the TEM work and N00014-20-1-2600 for the thin film growth effort.The work at Los Alamos National Laboratory was supported by the NNSA’s Laboratory Directed Research and Development Program and was performed,in part,at the Center for Integrated Nanotechnologies,an Office of Science User Facility operated for the U.S.Department of Energy Office of Science.Los Alamos National Laboratory,an affirmative action equal opportunity employer,is managed by Triad National Security,LLC for the U.S.Department of Energy’s NNSA,under contract 89233218CNA000001.
文摘Two-dimensional(2D)layered oxides have recently attracted wide attention owing to the strong coupling among charges,spins,lattice,and strain,which allows great flexibility and opportunities in structure designs as well as multifunctionality exploration.In parallel,plasmonic hybrid nanostructures exhibit exotic localized surface plasmon resonance(LSPR)providing a broad range of applications in nanophotonic devices and sensors.A hybrid material platform combining the unique multifunctional 2D layered oxides and plasmonic nanostructures brings optical tuning into the new level.In this work,a novel self-assembled Bi2MoO6(BMO)2D layered oxide incorporated with plasmonic Au nanoinclusions has been demonstrated via one-step pulsed laser deposition(PLD)technique.Comprehensive microstructural characterizations,including scanning transmission electron microscopy(STEM),differential phase contrast imaging(DPC),and STEM tomography,have demonstrated the high epitaxial quality and particle-in-matrix morphology of the BMO-Au nanocomposite film.DPC-STEM imaging clarifies the magnetic domain structures of BMO matrix.Three different BMO structures including layered supercell(LSC)and superlattices have been revealed which is attributed to the variable strain states throughout the BMO-Au film.Owing to the combination of plasmonic Au and layered structure of BMO,the nanocomposite film exhibits a typical LSPR in visible wavelength region and strong anisotropy in terms of its optical and ferromagnetic properties.This study opens a new avenue for developing novel 2D layered complex oxides incorporated with plasmonic metal or semiconductor phases showing great potential for applications in multifunctional nanoelectronics devices.
基金This work was supported by the U.S.Office of Naval Research(ONR,N00014-20-1-2600)J.B.acknowledges the support from the Laboratory Directed Research and Development program at Sandia National Laboratories,a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia,LLC,a wholly owned subsidiary of Honeywell International,Inc.,for the U.S.Department of Energy's National Nuclear Security Administration under contract DE-NA-003525+1 种基金The high-resolution STEM imaging work was funded by the U.S.National Science Foundation(DMR-2016453)The article describes objective technical results and analysis.Any subjective views or opinions that might be expressed in the article do not necessarily represent the views of the U.S.Department of Energy or the United States Government。
文摘Multiferroics are an intriguing family of materials due to the simultaneous presence of two ferroic orderings,namely,ferroelectricity and ferromagnetism.They are scientifically and technologically important and have numerous potential applications,such as four-state logic memories and multiferroic tunneling junctions.However,the growth of epitaxial singlephase multiferroic thin films typically requires single crystalline oxide substrates,which hinders their future integration with Sibased devices.In this study,we report a generalized synthesis method that uses the polydimethylsiloxane(PDMS)-assisted wetetching method with an Sr_(3)Al_(2)O_(6)(SAO)sacrificial layer to transfer freestanding single-phase multiferroic Bi_(2)NiMnO_(6)(BNMO)films from conventional SrTiO_(3)(STO)substrates onto a Si wafer.The structures and properties of the films have been characterized before and after the transfer.These transferred films possess good multiferroic properties on Si wafers,indicating full compatibility with modern Si technology.This method can be generally applicable to other Bi-based multiferroic materials as well.Lastly,the original STO substrates after the transfer process have been recycled for preparing new batches of freestanding BNMO films,indicating a low-cost and sustainable method for manufacturing large-volume freestanding complex oxide thin films.
