초록 ▼

※ 총괄과제:
- 지속적이고 체계적인 국내 이용자 연구 네트워크를 형성.
- 해외 시설 이용으로 겪게 되는 장벽을 해소하여 참여연구원의 장기적인 활용은 물론 국내 신규 이용자의 진입을 활성화.
- 해외 빔라인 과학자와 국내 이용자 간의 공동연구관계 및 국제 경쟁력 있는 공동 연구과제를 도출.
※ 제1세부과제:
- 미소자기 전산모사를 활용하여 3차원자성 자기 솔리톤의 위상기하학적 구조의 해석과 동적 거동 조사.
- 3차원 자성 솔리톤인 Bloch point의 동적 거동을 세계최초 관측 성공.
※

※ 총괄과제:
- 지속적이고 체계적인 국내 이용자 연구 네트워크를 형성.
- 해외 시설 이용으로 겪게 되는 장벽을 해소하여 참여연구원의 장기적인 활용은 물론 국내 신규 이용자의 진입을 활성화.
- 해외 빔라인 과학자와 국내 이용자 간의 공동연구관계 및 국제 경쟁력 있는 공동 연구과제를 도출.
※ 제1세부과제:
- 미소자기 전산모사를 활용하여 3차원자성 자기 솔리톤의 위상기하학적 구조의 해석과 동적 거동 조사.
- 3차원 자성 솔리톤인 Bloch point의 동적 거동을 세계최초 관측 성공.
※ 제2세부과제:
- 기존 고온고압 장치의 온도-압력 범위를 확장(~10 GPa + 850℃), Fe-함유 광물의 온도 및 압력에 따른 구조화학적 변화를 규명.
- 다양한 광물 및 합성물에 대해 실시간 XRD 및 Raman/IR 분광법을 이용해 압력 및 온도에 따른 화학반응 및 상전이 연구에 대한 다수의 우수한 성과(SCI 논문 10편 게재)를 획득.
- 섭입대 조건에서 점토광물과 물과의 상호작용을 새로이 규명(Nature Geoscience), 실리콘 나노시트에 대한 압력처리를 통해 나노와이어로 전환됨(Nature Communications).
※ 제3세부과제:
- NiPS3의 경우 음의 전하전달에너지를 갖는 독특한 바닥상태 전자구조를 가짐을 확인.
※ 제4세부과제:
- 반강자성체와 강자성체의 복합물로 이루어진 3차원의 계면 구조를 가지는 박막의 제작이 가능함을 확인.
- 나노 복합 구조 박막 내 반강자성체가 인접한 강자성체에 미치는 영향을 자구의 동적 반응을 통해 확인.
- 이종 물질 원자간 스핀이 반강자성체와 같이 반평행결합을 가지는 페리자성체 단일 박막에서 스커미온 구조를 가지는 버블 페이즈를 확인하고 이를 외부 자극을 통한 이동 및 제어의 가능성을 확인.
※ 제5세부과제:
- 그동안 간과하던 자유도인 스핀-오빗 결합의 효과가 큰 강상관계의 양자 발현물성을 찾는 응집물리 분야의 새로운 접근법 제시.
- 고품질 단결정 GaTa₄Se₈을 이용한 RIXS 실험 수행으로 새로운 양자 기저 상태인 J_eff = 3/2 시스템임을 최초 규명.
※ 제6세부과제:
- 다강체 2H-BaMnO₃ 단결정에서 관찰되는 전기분극의 발현이 Hexagonal LnMnO₃ 와 동일한 Z₂×Z₃ 대칭성에 의한 것임을 처음으로 입증.
-양자자성체 NiTe₂O₅ 의 자기구조를 명확히 밝히고, order parameter 의 universality class가 매우 특이한 class 속해 있는 것을 발견.
※ 제7세부과제:
- Advanced Photon Source의 general user beamtime과 staff beamtime을 확보하면서 다양한 종류의 계면을 갖는 시료들을 조사 및 구하는 동시에 방사광에서 모든 엑스선 bunch를 사용할 수 있도록 oscilloscope을 기반으로 한 data acquisition module의 개발을 준비함.
※ 제8세부과제:
- 세계최초로 나노초 전류펄스 인가로 인한 스커미온의 호흡 운동을 관측하였으며, 전류 세기에 따라 이동 운동이나 호흡 운동이 나타날 수 있음을 밝힘
- 세계최초로 페리자성체에서 스커미온을 관측하였으며, 효율적 전류인가 이동도를 측정하였음. 특히 강자성체 기반 스커미온에 비해 스커미온 홀 효과가 월등히 작은 것을 발견하였음.
※ 제9세부과제:
- 스침각 엑스선 산란을 이용한 페로브스카이트 양자점 발광소자의 결정 구조 연구를 통해 양자점의 결정 구조 배열이 좋을수록 박막 소자의 발광 특성이 좋아지는 것을 확인.
- 반사모드 결맞는 연엑스선 공명 자기 산란 이미징 실험을 통해 박막 형태의 나노 자기 도메인 이미지를 얻을 수 있는 기초 실험을 수행.
※ 제10세부과제:
- 편광된 방사광을 이용하여 HVO2의 전자 구조를 성공적으로 분석함.
- 유사대기압 상태에서 VO2 박막의 수소 도핑 시 실시간 전자구조 분석을 통하여 수소 도핑의 메커니즘을 규명.

(출처 : 보고서 요약서 3p)

Abstract ▼

Ⅱ. Aims of the project
The purpose of this research proposal is to develop a network of Korean researchers for the study of spintronic and advanced functional materials using at advanced overseas synchrotron facilities. This project will enable Korean users to overcome the barrier of using a fore

Ⅱ. Aims of the project
The purpose of this research proposal is to develop a network of Korean researchers for the study of spintronic and advanced functional materials using at advanced overseas synchrotron facilities. This project will enable Korean users to overcome the barrier of using a foreign facility, and will bring new Korean researchers to these facilities. In particular, it is intended that a longstanding and extensive collaboration can be formed between reseachers at Korean intistutions and Korean national scientists at overseas institutions. This could lead to a larger scale international research project.
※ 1^st detailed task: Our goal is observing the dynamic behavior of 3D magnetic soliton by using Magnetic Transmission X-ray Microscopy (MTXM) in lawrence berkeley national laboratory, USA and finding out the fundamentals on a magnetic soliton’s dynamics and providing the basic principle of manipulation.
※ 2^nd detailed task: This project is to understand and discover novel structural, chemical and magnetic properties of structurally-complex minerals and compounds under extreme conditions by utilizing specialized high-pressure and high-temperature instrumentations available at synchrotron facilities.
※ 3^rd detailed task:Investigation on microscopic magnetic domain structure by using scanning e transmission X-ray microscope.
※ 4^th detailed task:Through the understandings and arbitrary controls of structures as well as the dynamic behaviors of magnetic domains inside the antiferromagnetic material, we attempt to utilize the antiferromagnetic material for the spintronics applications.
※ 5^th detailed task: We need an alternative explanation to explore new quantum emergent properties of the correlated systems-including ‘spin-orbit coupling’.
※ 6^th detailed task: Using X-ray magnetic scattering technique under the extreme environment, such as 60 Tesla pulse magnet, ultra high voltage, we investigate physical origin of exotic ground states of strongly correlated electrons.
※ 7^th detailed task: We intend to measure transient structural dynamics taking place under nanosecond at various semiconductor and metals as well as complex heterostructure interfaces. In more detail, we plan to study.
※ 8^th detailed task: We intend to realize the deterministic generation and individual manipulation of magnetic Skyrmions using state-of-the-art x-ray techniques available at advanced synchrotron facilities.
※ 9^th detailed task: An advanced experimental technique that cannot be performed in the Korean synchrotron radiation accelerators, such as x-ray resonance (magnetic) scattering, reflection mode x-ray resonance coherent scattering and laser pump picosecond time-resolved x-ray diffraction experiments were carried out at the Advanced Photon Source (APS) in the United States.
※ 10^th detailed task:The main goal, we aimed to clarify the principle by analyzing the electronic structure of the strongly correlated materials at ambient pressure. Based on the goal of this sub-project, we will develop technologies for ultra-low power consumption memory devices as well as hydrogen storage and hydrogen-doped neuromorphic device.

Ⅲ. The scope of the project activities
The main research topic of the center is the investigation of spintronic materials and advanced functional materials using multiple state-of-the-art x-ray measurements systems at US national synchrotron facilities.The main focus will be on the structural and dynamic properties of such materials. The aim is to use facilities unavailable in Korea to broaden the research area. Also it is intended to stimulate collaboration between different x-ray measurement techniques. Korean national scientist are beamline staffs at the aforementioned beamlines which will facilitate research collaborations between the beamline and Korean researchers. Annual users meeting among the project leaders and students will be held for further development of research projects.
※ 1^st detailed task: Exploring manipulation methods for 3D magnetic soliton based on the simulation and experiment results.
※ 2^nd detailed task:We will use dedicated extreme conditions beamlines at Advanced Photon Source (APS) and Stanford Synchrotron Radiation Lightsource (SSRL) to investigate structural, chemical and magnetic properties of structurally-complex minerals and compounds under high-pressure and high-temperature conditions.
※ 3^rd detailed task:Identification of layer-dependent electronic structures of FePS3 and NiPS3 magnetic Van der Waals materials and unique ground state of NiPS3 with negative charge transfer energy.
※ 4^th detailed task: Compound nanostructures are formed from both ferromagnetic and antiferromagnetic materials in order to tailor the magnetic domain related properties based on the relationships between the structure and spin configurations of antiferromagnetic materials.
※ 5^th detailed task:We demonstrated new quantum emergent properties (jeff system) of lacunar spinel (GaTa4Se8), which is a newly proposed material in theory.
※ 6^th detailed task:Study of abnormal continuous spin-flop transition originated from quartic anisotropy associated with structural chirality.
※ 7^th detailed task:In this project, our primary goal is to develop proper infrastructures to study generation and propagation of coherent acoustic phonons at atomic length and time-scales by making uses of time-resolved x-ray scattering facilities abroad such as APS and LCLS.
※ 8^th detailed task:Investigation of chiral magnetic materials showing skyrmion spin structures and Current induced ultrafast skyrmion dynamics.
※ 9^th detailed task: We have studied the charge transfer at the functional oxide interface using X - ray resonance scattering. We also measured the anisotropic x-ray diffraction with Mn K-edge and Ir L-edge using 2D detector of APS 6-ID beamline. We measured the picosecond time-resolved by using the APS 7-ID beamline's laser pump-x-ray probe technique for the study of metal-semiconductor interface thermal conductivity using picosecond time-resolved X-ray diffraction experiments.
※ 10^th detailed task: Establishment of a database of changes in electrical characteristics due to hydrogen doping of strongly correlated materials. Analysis of real-time electronic structure change at ambient pressure using Operando-XPS system.

Ⅳ. Achievements and contributions
(1) Utilization of overseas synchrotron radiation facilities
(2) Journal papers publications : 29 SCI international papers,, Conference: 32 times Announcement.
(3) regular meetings
- Participants in detailed tasks were involved.
- Discussed the operation and research results of the project team.
(4) Homepage managemen
(https://sites.google.com/site/advancedfunctionalmaterialsrsa/home)
※ 1^st detailed task: he dynamic behavior of the 3D spin structure was investigated through MTXM two-bunch mode and simulation, finally the control method was suggested.
※ 2^nd detailed task:By utilizing specialized beamlines and programs at APS and SSRL we will acquire advanced techniques and novel findings to gain a leading role in the extreme conditions science community and contribute to the construction of a dedicated high-pressure beamline at Pohang Accelerator Laboratory.
※ 3^rd detailed task: We have studied the electronic structure of transition metal trisulfide phosphorus, one of the two - dimensional magnetic materials that could possibly be a material for new spin nano devices. Information about electronic structure was obtained by theoretical calculations.
※ 4^th detailed task : New nanomaterials with previsously unanticipated properties can be achieved and new phenomena in the antiferromagnetic material will be explored.
※ 5^th detailed task: In this project, we proposed a new experimental approach based on RIXS and strong spin-orbit coupling systems. We systematically synthesized high-quality thin films and single crystals using our original techniques.
※ 6^th detailed task:Experimental demonstration of reverse of octahedra rotation in hybrid improper ferroelectric.
※ 7^th detailed task: Direct measurement of melting (thermal and non-thermal) phenomena in solids.
※ 8^th detailed task: We measured nanosecond-dynamics of a 100nm-diameter magnetic skyrmion during a current pulse application, using a time-resolved pump-probe soft X-ray imaging technique. We demonstrate that distinct dynamic excitation states of magnetic skyrmions, triggered by current-induced spin-orbit torques, can be reliably tuned by changing the magnitude of spin-orbit torques. Our findings show that the dynamics of magnetic skyrmions can be controlled by the spin-orbit torque on the nanosecond time scale.
※ 9^th detailed task:
- Reflection-mode coherent x-ray resonance magnetic scattering imaging experiments were performed to obtain a thin-film nano-magnetic domain image. The results were published in the Nanoscale
- Experiments were carried out to quantitatively determine the absorption spectrum of the interface in the functional oxide heterojunction structure using x-ray resonant scattering. We are conducting quantitative analysis of the experimental data measured from a [SrMnO3/SrIrO3]x10 superlattice at the Mn L-edges in the soft x-ray region and at the Ir L-edges in the hard x-ray region.
- A picosecond time-resolved x-ray diffraction experiment was used to study metal-semiconductor interface thermal conduction. Especially, we could quantitatively analyze the mechanism of impulsive coherent phonons transferred into Si crystal by laser pulse applied depending on the thickness of Cr metal thin film.
※ 10^th detailed task:
- the crystal structure of correlated oxides (VO2, NdNiO3) films hydrogenated were investigated using in-situ XRD. After hydrogenation, films were volume expanded and changed electronic structures.
- n-situ XRD results show that hydrogen diffusion kinetics and electron lattice coupling were strongly depending on facet orientation of the VO2 epilayer.
- We perfoemed in-situ XPS and operando XPS to measure the time-dependent lattice expansion and change of valence of each atom.

Ⅴ. Applications and operation plan
※ General
- The broadening of the research field by using facilities unavailable in Korea.
- Obtaining knowledge of advanced measurement set-ups such as pico-second time resolved spin and phonon dynamics measurement systems and nanometer spatially resolved magnetic imaging measurement systems.
- New and original research on structural and magnetic properties of spintronic and advanced functional materials in extreme environments (high pressure (~Mbar), high magnetic field (60 T pulse)).
※ 1^st detailed task:Understanding topological magnetic structure - Verification of theory based on the micro-magnetic simulation - Verification of experiment using high resolution MTXM can be used to study of various magnetic structure and topological structure.
※ 2^nd detailed task:Study of minerals and compounds under extreme conditions has been developed in advanced countries equipped with specialized instrumentations at the 3rd generation synchrotrons but is still rare in Korea. Through this project. we are expected to nurture extreme conditions science and techniques at PLS-II and PAL-XFEL and lead to discover novel structural and chemical properties of minerals and compounds.
※ 3^rd detailed task:Investigation of layer-dependent electronic structures and magnetic properties of magnetic Van der Waals materials by using magnetic transmission X-ray microscope based on synchrotron radiations.
※ 4^th detailed task: An antiferromagnet is introduced into magnetic studies concentrated on ferromagnetic materials such as information storage, permanent magnets, and spintronic devices.So we expect to expand the base of magnetic materials.
※ 5^th detailed task:Exploring quantum emergent properties of correlated systems will overcome the conventional trial-error approach. Recently, some researchers suggested an innovative way to search for the properties via controlling ‘spin-orbit coupling’ rather than the conventional physical picture (charge-spin-lattice).
※ 6^th detailed task:emonstration of electrical reverse magnetism using hybrid improper ferroelectricity.Measurement of high speed ensemble averaged motions of atoms.
※ 7^th detailed task:Generation of broad frequency acoustic phonons and its propagation through various interfaces.
※ 8^th detailed task: The deterministic writing and deleting of single isolated skyrmions at room temperature in ferrimagnetic GdFeCo films with a device-compatible stripline geometry is demonstrated. The process is driven by the application of current pulses, which induce spin-orbit torques, and is directly observed using a time-resolved nanoscale X-ray imaging technique. The current pulse profile for the efficient and deterministic writing and deleting process is developed.
※ 9^th detailed task: A study of the crystalline structure of Perovskite quantum-dot light-emitting diodes using grazing-incidence x-ray scattering showed that the better the crystal structure of the quantum dots, the better the luminescence characteristics of the thin film device.
※ 10^th detailed task:
- It is expected to accelerate development of hydrogen storage based on oxide as well as development of neuromorphic device and ultra low power memory device through hydrogen doping of strongly correlated materials.
- Operando-XPS can be able to train doctor-level human resources and operate the AP-XPS system, that will be installed in Pohang Accelerator Laboratory at 2019, more stably.

(출처 : SUMMARY 11p)

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 보고서 요약서 ... 3
• 요약문 ... 6
• SUMMARY ... 11
• CONTENTS ... 17
• 목차 ... 18
• 제1장 연구개발과제의 개요 ... 19
• 제1절. 연구 개발의 목적 ... 19
• 제2절. 연구개발의 범위 ... 20
• 제2장 국내외 기술개발 현황 ... 24
• 제1절. 1세부과제 현황 ... 24
• 제2절. 2세부과제 현황 ... 24
• 제3절. 3세부과제 현황 ... 24
• 제4절. 4세부과제 현황 ... 25
• 제5절. 5세부과제 현황 ... 25
• 제6절. 6세부과제 현황 ... 25
• 제7절. 7세부과제 현황 ... 26
• 제8절. 8세부과제 현황 ... 26
• 제9절. 9세부과제 현황 ... 27
• 제10절. 10세부과제 ... 27
• 제3장 연구개발수행 내용 및 결과 ... 28
• 제1절. 연구 개발 수행 내용 ... 28
• 제2절. 국내 연구자의 해외 방사광 가속기 이용 추이 ... 37
• 제4장 목표달성도 및 관련분야에의 기여도 ... 38
• 제1절. 1차년도 연구개발 목표의 달성도 ... 38
• 제2절. 2차년도의 연구개발 목표의 달성도 ... 39
• 제3절. 3차년도 연구개발 목표의 달성도 ... 42
• 제4절. 관련 분야에의 기여도 ... 45
• 제5장 연구개발결과의 활용계획 ... 47
• 제6장 연구개발과정에서 수집한 해외과학기술정보 ... 49
• 제7장 연구장비의 구축 및 활용 결과 ... 50
• 제8장 참고문헌 ... 51
• 연구성과(연구사업지원시스템 입력성과) ... 58
• 끝페이지 ... 59