Proximity effects between superconductors and ferromagnets(SC/FM)hold paramount importance in comprehending the spin competition transpiring at their interfaces.This competition arises from the interplay between Coope...Proximity effects between superconductors and ferromagnets(SC/FM)hold paramount importance in comprehending the spin competition transpiring at their interfaces.This competition arises from the interplay between Cooper pairs and ferromagnetic exchange interactions.The proximity effects between transition metal nitrides(TMNs)are scarcely investigated due to the formidable challenges of fabricating high-quality SC/FM interfaces.We fabricated heterostructures comprising SC titanium nitride(TiN)and FM iron nitride(Fe_(3)N)with precise chemical compositions and atomically well-defined interfaces.The magnetoresistance of Fe_(3)N/TiN heterostructures shows a distinct magnetic anisotropy and strongly depends on the external perturbations.Moreover,the superconducting transition temperatureT_(C) and critical field of TiN experience notable suppression when proximity to Fe_(3)N.We observe the intriguing competition of interfacial spin orientations near𝑇T_(C)(∼1.25 K).These findings not only add a new materials system for investigating the interplay between superconductor and ferromagnets,but also potentially provide a building block for future research endeavors and applications in the realms of superconducting spintronic devices.展开更多
Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom,offering a promise for the realization of novel electronic states.In this wor...Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom,offering a promise for the realization of novel electronic states.In this work,we report the structural and transport phase transition in an oxide semimetal,SrNbO_(3),achieved through effective anion doping.Notably,the resistivity increased by more than three orders of magnitude at room temperature upon nitrogendoping.The extent of electronic modulation in SrNbO_(3)is strongly correlated with misfit strain,underscoring its phase instability to both chemical doping and crystallographic symmetry variations.Using first-principles calculations,we discern that elevating the level of nitrogen doping induces an upward shift in the conductive bands of SrNbO_(3−δ)N_(δ).Consequently,a transition from a metallic state to an insulating state becomes apparent as the nitrogen concentration reaches a threshold of 1/3.This investigation shows effective anion engineering in oxide semimetals,offering pathways for manipulating their physical properties.展开更多
Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in ...Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in the context of traditional strain engineering methods.In this work,by using the interphase strain,we achieve a ferromagnetic state with enhanced Curie temperature and a room-temperature polar state in EuO secondary phase-tunned EuTiO_(3) thin films.A combination of atomic-scale electron microscopy and synchrotron X-ray spectroscopy unravels the underlying mechanisms of the ferroelectric and ferromagnetic properties enhancement.Wherein,the EuO secondary phase is found to be able to dramatically distort the TiO_6 octahedra,which favors the non-centrosymmetric polar state,weakens antiferromagnetic Eu-Ti-Eu interactions,and enhances ferromagnetic Eu-O-Eu interactions.Our work demonstrates the feasibility and effectiveness of interphase strain engineering in simultaneously promoting ferroelectric and ferromagnetic performance,which would provide new thinking on the property regulation of numerous strongly correlated functional materials.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2020YFA0309100 and 2019YFA0308500)the National Natural Science Foundation of China(Grant Nos.U22A20263,52250308,and 11974390)+3 种基金the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-084)(E.J.G.)Special Research Assistant(Q.J.),the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB33030200)(K.J.)the China Postdoctoral Science Foundation(Grant No.2022M723353)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology(Grant No.HTCSNS-DG-CD-0080/2021).
文摘Proximity effects between superconductors and ferromagnets(SC/FM)hold paramount importance in comprehending the spin competition transpiring at their interfaces.This competition arises from the interplay between Cooper pairs and ferromagnetic exchange interactions.The proximity effects between transition metal nitrides(TMNs)are scarcely investigated due to the formidable challenges of fabricating high-quality SC/FM interfaces.We fabricated heterostructures comprising SC titanium nitride(TiN)and FM iron nitride(Fe_(3)N)with precise chemical compositions and atomically well-defined interfaces.The magnetoresistance of Fe_(3)N/TiN heterostructures shows a distinct magnetic anisotropy and strongly depends on the external perturbations.Moreover,the superconducting transition temperatureT_(C) and critical field of TiN experience notable suppression when proximity to Fe_(3)N.We observe the intriguing competition of interfacial spin orientations near𝑇T_(C)(∼1.25 K).These findings not only add a new materials system for investigating the interplay between superconductor and ferromagnets,but also potentially provide a building block for future research endeavors and applications in the realms of superconducting spintronic devices.
基金CAS Project for Young Scientists in Basic Research,Grant/Award Number:YSBR‐084China Postdoctoral Science Foundation,Grant/Award Number:2022M723353+4 种基金Jiangsu Funding Program for Excellent Postdoctoral TalentStrategic Priority Research Program(B)of the Chinese Academy of Sciences,Grant/Award Number:XDB33030200National Natural Science Foundation of China,Grant/Award Numbers:11974390,U22A20263,52250308,12347185National Key Basic Research Program of China,Grant/Award Numbers:2020YFA0309100,2019YFA0308500Postdoctoral Fellowship Program of CPSF,Grant/Award Number:GZC20230443。
文摘Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom,offering a promise for the realization of novel electronic states.In this work,we report the structural and transport phase transition in an oxide semimetal,SrNbO_(3),achieved through effective anion doping.Notably,the resistivity increased by more than three orders of magnitude at room temperature upon nitrogendoping.The extent of electronic modulation in SrNbO_(3)is strongly correlated with misfit strain,underscoring its phase instability to both chemical doping and crystallographic symmetry variations.Using first-principles calculations,we discern that elevating the level of nitrogen doping induces an upward shift in the conductive bands of SrNbO_(3−δ)N_(δ).Consequently,a transition from a metallic state to an insulating state becomes apparent as the nitrogen concentration reaches a threshold of 1/3.This investigation shows effective anion engineering in oxide semimetals,offering pathways for manipulating their physical properties.
基金supported by the National Key Basic Research Program of China(Nos.2020YFA0309100 and 2019YFA0308500)the National Natural Science Foundation of China(Nos.21825102,22001014,11294029,11974390,11721404)+6 种基金the China National Postdoctoral Program for Innovative Talents(No.BX20200043)China Postdoctoral Science Foundation(No.2021M690366)the Beijing Nova Program of Science and Technology(No.Z191100001119112)the Beijing Natural Science Foundation(No.2202060)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(No.XDB33030200)the Fundamental Research Funds for the Central Universities,China(Nos.06500145 and FRF-IDRY-20–039)State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF202110)。
文摘Interphase strain engineering provides a unique methodology to significantly modify the lattice structure across a single film,enabling the emergence and manipulation of novel functionalities that are inaccessible in the context of traditional strain engineering methods.In this work,by using the interphase strain,we achieve a ferromagnetic state with enhanced Curie temperature and a room-temperature polar state in EuO secondary phase-tunned EuTiO_(3) thin films.A combination of atomic-scale electron microscopy and synchrotron X-ray spectroscopy unravels the underlying mechanisms of the ferroelectric and ferromagnetic properties enhancement.Wherein,the EuO secondary phase is found to be able to dramatically distort the TiO_6 octahedra,which favors the non-centrosymmetric polar state,weakens antiferromagnetic Eu-Ti-Eu interactions,and enhances ferromagnetic Eu-O-Eu interactions.Our work demonstrates the feasibility and effectiveness of interphase strain engineering in simultaneously promoting ferroelectric and ferromagnetic performance,which would provide new thinking on the property regulation of numerous strongly correlated functional materials.
