1
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Yoo C, Hartanto J, Saini B, Tsai W, Thampy V, Niavol SS, Meng AC, McIntyre PC. Atomic Layer Deposition of WO 3-Doped In 2O 3 for Reliable and Scalable BEOL-Compatible Transistors. Nano Lett 2024; 24:5737-5745. [PMID: 38686670 DOI: 10.1021/acs.nanolett.4c00746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Tungsten oxide (WO3) doped indium oxide (IWO) field-effect transistors (FET), synthesized using atomic layer deposition (ALD) for three-dimensional integration and back-end-of-line (BEOL) compatibility, are demonstrated. Low-concentration (1∼4 W atom %) WO3-doping in In2O3 films is achieved by adjusting cycle ratios of the indium and tungsten precursors with the oxidant coreactant. Such doping suppresses oxygen deficiency from In2O2.5 to In2O3 stoichiometry with only 1 atom % W, allowing devices to turn off stably and enhancing threshold voltage stability. The ALD IWO FETs exhibit superior performance, including a low subthreshold slope of 67 mV/decade and negligible hysteresis. Strong tunability of the threshold voltage (Vth) is achieved through W concentration tuning, with 2 atom % IWO FETs showing an optimized Vth for enhancement-mode and a high drain current. ALD IWO FETs have remarkable stability under bias stress and nearly ideal performance extending to sub-100 nm channel lengths, making them promising candidates for high-performance monolithic 3D integrated devices.
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Affiliation(s)
- Chanyoung Yoo
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Department of Materials Science and Engineering, Hongik University, Seoul 04066, Republic of Korea
| | - Jonathan Hartanto
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Balreen Saini
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Wilman Tsai
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Vivek Thampy
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Somayeh Saadat Niavol
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Andrew C Meng
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Paul C McIntyre
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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2
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Huang F, Saini B, Yu Z, Yoo C, Thampy V, He X, Baniecki JD, Tsai W, Meng AC, McIntyre PC, Wong S. Enhanced Switching Reliability of Hf 0.5Zr 0.5O 2 Ferroelectric Films Induced by Interface Engineering. ACS Appl Mater Interfaces 2023; 15:50246-50253. [PMID: 37856882 DOI: 10.1021/acsami.3c08895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Ferroelectric materials have been widely researched for applications in memory and energy storage. Among these materials and benefiting from their excellent chemical compatibility with complementary metal-oxide-semiconductor (CMOS) devices, hafnia-based ferroelectric thin films hold great promise for highly scaled semiconductor memories, including nonvolatile ferroelectric capacitors and transistors. However, variation in the switched polarization of this material during field cycling and a limited understanding of the responsible mechanisms have impeded their implementation in technology. Here, we show that ferroelectric Hf0.5Zr0.5O2 (HZO) capacitors that are nearly free of polarization "wake-up"─a gradual increase in switched polarization as a function of the number of switching cycles─can be achieved by introducing ultrathin HfO2 buffer layers at the HZO/electrodes interface. High-resolution transmission electron microscopy (HRTEM) reveals crystallite sizes substantially greater than the film thickness for the buffer layer capacitors, indicating that the presence of the buffer layers influences the crystallization of the film (e.g., a lower ratio of nucleation rate to growth rate) during postdeposition annealing. This evidently promotes the formation of a polar orthorhombic (O) phase in the as-fabricated buffer layer samples. Synchrotron X-ray diffraction (XRD) reveals the conversion of the nonpolar tetragonal (T) phase to the polar orthorhombic (O) phase during electric field cycling in the control (no buffer) devices, consistent with the polarization wake-up observed for these capacitors. The extent of T-O transformation in the nonbuffer samples is directly dependent on the duration over which the field is applied. These results provide insight into the role of the HZO/electrodes interface in the performance of hafnia-based ferroelectrics and the mechanisms driving the polarization wake-up effect.
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Affiliation(s)
- Fei Huang
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Balreen Saini
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Zhouchangwan Yu
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Chanyoung Yoo
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Vivek Thampy
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Xiaoqing He
- Electron Microscopy Core Facility and Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211, United States
| | - John D Baniecki
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Wilman Tsai
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Andrew C Meng
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Paul C McIntyre
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Simon Wong
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
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3
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Stone KH, Cosby MR, Strange NA, Thampy V, Walroth RC, Troxel Jr C. Remote and automated high-throughput powder diffraction measurements enabled by a robotic sample changer at SSRL beamline 2-1. J Appl Crystallogr 2023; 56:1480-1484. [PMID: 37791352 PMCID: PMC10543666 DOI: 10.1107/s1600576723007148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 08/14/2023] [Indexed: 10/05/2023] Open
Abstract
The general-purpose powder diffractometer beamline (BL2-1) at the Stanford Synchrotron Radiation Lightsource (SSRL) is described. The evolution of design and performance of BL2-1 are presented, in addition to current operating specifications, applications and measurement capabilities. Recent developments involve a robotic sample changer enabling high-throughput X-ray diffraction measurements, applicable to mail-in and remote operations. In situ and operando capabilities to measure samples with different form factors (e.g. capillary, flat plate or thin film, and transmission) and under variable experimental conditions are discussed. Several example datasets and accompanying Rietveld refinements are presented.
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Affiliation(s)
- Kevin H. Stone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Monty R. Cosby
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Nicholas A. Strange
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Vivek Thampy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Richard C. Walroth
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Charles Troxel Jr
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
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4
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Martin AA, Wang J, DePond PJ, Strantza M, Forien JB, Gorgannejad S, Guss GM, Thampy V, Fong AY, Weker JN, Stone KH, Tassone CJ, Matthews MJ, Calta NP. A laser powder bed fusion system for operando synchrotron x-ray imaging and correlative diagnostic experiments at the Stanford Synchrotron Radiation Lightsource. Rev Sci Instrum 2022; 93:043702. [PMID: 35489885 DOI: 10.1063/5.0080724] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Laser powder bed fusion (LPBF) is a highly dynamic multi-physics process used for the additive manufacturing (AM) of metal components. Improving process understanding and validating predictive computational models require high-fidelity diagnostics capable of capturing data in challenging environments. Synchrotron x-ray techniques play a vital role in the validation process as they are the only in situ diagnostic capable of imaging sub-surface melt pool dynamics and microstructure evolution during LPBF-AM. In this article, a laboratory scale system designed to mimic LPBF process conditions while operating at a synchrotron facility is described. The system is implemented with process accurate atmospheric conditions, including an air knife for active vapor plume removal. Significantly, the chamber also incorporates a diagnostic sensor suite that monitors emitted optical, acoustic, and electronic signals during laser processing with coincident x-ray imaging. The addition of the sensor suite enables validation of these industrially compatible single point sensors by detecting pore formation and spatter events and directly correlating the events with changes in the detected signal. Experiments in the Ti-6Al-4V alloy performed at the Stanford Synchrotron Radiation Lightsource using the system are detailed with sufficient sampling rates to probe melt pool dynamics. X-ray imaging captures melt pool dynamics at frame rates of 20 kHz with a 2 µm pixel resolution, and the coincident diagnostic sensor data are recorded at 470 kHz. This work shows that the current system enables the in situ detection of defects during the LPBF process and permits direct correlation of diagnostic signatures at the exact time of defect formation.
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Affiliation(s)
- Aiden A Martin
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Jenny Wang
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Philip J DePond
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Maria Strantza
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | | | - Sanam Gorgannejad
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Gabriel M Guss
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Vivek Thampy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Anthony Y Fong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Johanna Nelson Weker
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Kevin H Stone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Christopher J Tassone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | - Nicholas P Calta
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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5
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Chitturi SR, Ratner D, Walroth RC, Thampy V, Reed EJ, Dunne M, Tassone CJ, Stone KH. Automated prediction of lattice parameters from X-ray powder diffraction patterns. J Appl Crystallogr 2021; 54:1799-1810. [PMID: 34963768 PMCID: PMC8662964 DOI: 10.1107/s1600576721010840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022] Open
Abstract
A key step in the analysis of powder X-ray diffraction (PXRD) data is the accurate determination of unit-cell lattice parameters. This step often requires significant human intervention and is a bottleneck that hinders efforts towards automated analysis. This work develops a series of one-dimensional convolutional neural networks (1D-CNNs) trained to provide lattice parameter estimates for each crystal system. A mean absolute percentage error of approximately 10% is achieved for each crystal system, which corresponds to a 100- to 1000-fold reduction in lattice parameter search space volume. The models learn from nearly one million crystal structures contained within the Inorganic Crystal Structure Database and the Cambridge Structural Database and, due to the nature of these two complimentary databases, the models generalize well across chemistries. A key component of this work is a systematic analysis of the effect of different realistic experimental non-idealities on model performance. It is found that the addition of impurity phases, baseline noise and peak broadening present the greatest challenges to learning, while zero-offset error and random intensity modulations have little effect. However, appropriate data modification schemes can be used to bolster model performance and yield reasonable predictions, even for data which simulate realistic experimental non-idealities. In order to obtain accurate results, a new approach is introduced which uses the initial machine learning estimates with existing iterative whole-pattern refinement schemes to tackle automated unit-cell solution.
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Affiliation(s)
- Sathya R. Chitturi
- Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Daniel Ratner
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | - Vivek Thampy
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Evan J. Reed
- Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Mike Dunne
- Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | - Kevin H. Stone
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
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6
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Abstract
Hybrid perovskites are a promising class of materials for a range of optoelectronic applications. Many material properties are dictated by the details of the synthetic process, yet a mechanistic understanding is lacking for the majority of these materials. We have studied the formation of methylammonium lead iodide films derived from a lead chloride precursor to understand both the casting solution chemistry and its influence on the final, largely chlorine-free, film. Using solution-phase extended X-ray absorption spectroscopy, we observe a halide exchange with the primary solution plumbate species identified as PbI2.5Cl0.33. The mixed halide plumbate solution species leads to formation of the crystalline intermediate phase of (CH3NH3)2PbI3Cl. Using in situ synchrotron X-ray diffraction, we show that compositional control of the casting solution can control the annealing kinetics of film formation. Our study demonstrates the importance of solution-phase chemistry and its impact on lead halide perovskite synthesis.
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Affiliation(s)
- Vivek Thampy
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Kevin H Stone
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
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7
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Thampy V, Fong AY, Calta NP, Wang J, Martin AA, Depond PJ, Kiss AM, Guss G, Xing Q, Ott RT, van Buuren A, Toney MF, Weker JN, Kramer MJ, Matthews MJ, Tassone CJ, Stone KH. Subsurface Cooling Rates and Microstructural Response during Laser Based Metal Additive Manufacturing. Sci Rep 2020; 10:1981. [PMID: 32029753 PMCID: PMC7005153 DOI: 10.1038/s41598-020-58598-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022] Open
Abstract
Laser powder bed fusion (LPBF) is a method of additive manufacturing characterized by the rapid scanning of a high powered laser over a thin bed of metallic powder to create a single layer, which may then be built upon to form larger structures. Much of the melting, resolidification, and subsequent cooling take place at much higher rates and with much higher thermal gradients than in traditional metallurgical processes, with much of this occurring below the surface. We have used in situ high speed X-ray diffraction to extract subsurface cooling rates following resolidification from the melt and above the β-transus in titanium alloy Ti-6Al-4V. We observe an inverse relationship with laser power and bulk cooling rates. The measured cooling rates are seen to correlate to the level of residual strain borne by the minority β-Ti phase with increased strain at slower cooling rates. The α-Ti phase shows a lattice contraction which is invariant with cooling rate. We also observe a broadening of the diffraction peaks which is greater for the β-Ti phase at slower cooling rates and a change in the relative phase fraction following LPBF. These results provide a direct measure of the subsurface thermal history and demonstrate its importance to the ultimate quality of additively manufactured materials.
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Affiliation(s)
- Vivek Thampy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States.
| | - Anthony Y Fong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Nicholas P Calta
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Jenny Wang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Aiden A Martin
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Philip J Depond
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Andrew M Kiss
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Gabe Guss
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Qingfeng Xing
- Division of Materials Science and Engineering, Ames Laboratory, Ames, IA, 50011, USA
| | - Ryan T Ott
- Division of Materials Science and Engineering, Ames Laboratory, Ames, IA, 50011, USA
| | - Anthony van Buuren
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Michael F Toney
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Johanna Nelson Weker
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Matthew J Kramer
- Division of Materials Science and Engineering, Ames Laboratory, Ames, IA, 50011, USA
| | - Manyalibo J Matthews
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Christopher J Tassone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States
| | - Kevin H Stone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, United States.
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8
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Martin AA, Calta NP, Khairallah SA, Wang J, Depond PJ, Fong AY, Thampy V, Guss GM, Kiss AM, Stone KH, Tassone CJ, Nelson Weker J, Toney MF, van Buuren T, Matthews MJ. Dynamics of pore formation during laser powder bed fusion additive manufacturing. Nat Commun 2019; 10:1987. [PMID: 31040270 PMCID: PMC6491446 DOI: 10.1038/s41467-019-10009-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/02/2019] [Indexed: 11/20/2022] Open
Abstract
Laser powder bed fusion additive manufacturing is an emerging 3D printing technique for the fabrication of advanced metal components. Widespread adoption of it and similar additive technologies is hampered by poor understanding of laser-metal interactions under such extreme thermal regimes. Here, we elucidate the mechanism of pore formation and liquid-solid interface dynamics during typical laser powder bed fusion conditions using in situ X-ray imaging and multi-physics simulations. Pores are revealed to form during changes in laser scan velocity due to the rapid formation then collapse of deep keyhole depressions in the surface which traps inert shielding gas in the solidifying metal. We develop a universal mitigation strategy which eliminates this pore formation process and improves the geometric quality of melt tracks. Our results provide insight into the physics of laser-metal interaction and demonstrate the potential for science-based approaches to improve confidence in components produced by laser powder bed fusion. Laser-matter interactions during laser powder bed fusion additive manufacturing remain poorly understood. Here, the authors combine in situ X-ray imaging and finite element simulations to show how detrimental pores form under printing conditions and develop a strategy to suppress them.
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Affiliation(s)
- Aiden A Martin
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Nicholas P Calta
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | | | - Jenny Wang
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Phillip J Depond
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Anthony Y Fong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Vivek Thampy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Gabe M Guss
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Andrew M Kiss
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Kevin H Stone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Christopher J Tassone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Johanna Nelson Weker
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Michael F Toney
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Tony van Buuren
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
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9
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Chen XM, Mazzoli C, Cao Y, Thampy V, Barbour AM, Hu W, Lu M, Assefa TA, Miao H, Fabbris G, Gu GD, Tranquada JM, Dean MPM, Wilkins SB, Robinson IK. Charge density wave memory in a cuprate superconductor. Nat Commun 2019; 10:1435. [PMID: 30926816 PMCID: PMC6440992 DOI: 10.1038/s41467-019-09433-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 03/11/2019] [Indexed: 11/09/2022] Open
Abstract
Although CDW correlations are a ubiquitous feature of the superconducting cuprates, their disparate properties suggest a crucial role for pinning the CDW to the lattice. Here, we report coherent resonant X-ray speckle correlation analysis, which directly determines the reproducibility of CDW domain patterns in La1.875Ba0.125CuO4 (LBCO 1/8) with thermal cycling. While CDW order is only observed below 54 K, where a structural phase transition creates inequivalent Cu-O bonds, we discover remarkably reproducible CDW domain memory upon repeated cycling to far higher temperatures. That memory is only lost on cycling to 240(3) K, which recovers the four-fold symmetry of the CuO2 planes. We infer that the structural features that develop below 240 K determine the CDW pinning landscape below 54 K. This opens a view into the complex coupling between charge and lattice degrees of freedom in superconducting cuprates.
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Affiliation(s)
- X M Chen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA. .,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Y Cao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - V Thampy
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.,Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - A M Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - W Hu
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - M Lu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - T A Assefa
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - J M Tranquada
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
| | - S B Wilkins
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA.
| | - I K Robinson
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA. .,London Centre for Nanotechnology, University College, Gower St., London, WC1E 6BT, UK.
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10
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Chen BR, Sun W, Kitchaev DA, Mangum JS, Thampy V, Garten LM, Ginley DS, Gorman BP, Stone KH, Ceder G, Toney MF, Schelhas LT. Understanding crystallization pathways leading to manganese oxide polymorph formation. Nat Commun 2018; 9:2553. [PMID: 29959330 PMCID: PMC6026189 DOI: 10.1038/s41467-018-04917-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 05/29/2018] [Indexed: 11/09/2022] Open
Abstract
Hydrothermal synthesis is challenging in metal oxide systems with diverse polymorphism, as reaction products are often sensitive to subtle variations in synthesis parameters. This sensitivity is rooted in the non-equilibrium nature of low-temperature crystallization, where competition between different metastable phases can lead to complex multistage crystallization pathways. Here, we propose an ab initio framework to predict how particle size and solution composition influence polymorph stability during nucleation and growth. We validate this framework using in situ X-ray scattering, by monitoring how the hydrothermal synthesis of MnO2 proceeds through different crystallization pathways under varying solution potassium ion concentrations ([K+] = 0, 0.2, and 0.33 M). We find that our computed size-dependent phase diagrams qualitatively capture which metastable polymorphs appear, the order of their appearance, and their relative lifetimes. Our combined computational and experimental approach offers a rational and systematic paradigm for the aqueous synthesis of target metal oxides.
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Affiliation(s)
- Bor-Rong Chen
- Stanford Synchrotron Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Wenhao Sun
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Materials Science and Engineering, UC Berkeley, Berkeley, CA, 94720, USA
| | - Daniil A Kitchaev
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - John S Mangum
- Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USA
| | - Vivek Thampy
- Stanford Synchrotron Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Lauren M Garten
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - David S Ginley
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Brian P Gorman
- Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USA
| | - Kevin H Stone
- Stanford Synchrotron Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Gerbrand Ceder
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Department of Materials Science and Engineering, UC Berkeley, Berkeley, CA, 94720, USA.
| | - Michael F Toney
- Stanford Synchrotron Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
- Applied Energy Programs, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
| | - Laura T Schelhas
- Applied Energy Programs, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
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11
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Calta NP, Wang J, Kiss AM, Martin AA, Depond PJ, Guss GM, Thampy V, Fong AY, Weker JN, Stone KH, Tassone CJ, Kramer MJ, Toney MF, Van Buuren A, Matthews MJ. An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes. Rev Sci Instrum 2018; 89:055101. [PMID: 29864819 DOI: 10.1063/1.5017236] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ∼1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ∼50 × 100 μm area. We also discuss the utility of these measurements for model validation and process improvement.
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Affiliation(s)
- Nicholas P Calta
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Jenny Wang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Andrew M Kiss
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Aiden A Martin
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Philip J Depond
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Gabriel M Guss
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Vivek Thampy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Anthony Y Fong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Johanna Nelson Weker
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Kevin H Stone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Christopher J Tassone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Matthew J Kramer
- Division of Materials Science and Engineering, Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Michael F Toney
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Anthony Van Buuren
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Manyalibo J Matthews
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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12
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Rajasekaran S, Okamoto J, Mathey L, Fechner M, Thampy V, Gu GD, Cavalleri A. Probing optically silent superfluid stripes in cuprates. Science 2018; 359:575-579. [PMID: 29420290 DOI: 10.1126/science.aan3438] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 12/22/2017] [Indexed: 11/02/2022]
Abstract
Unconventional superconductivity in the cuprates coexists with other types of electronic order. However, some of these orders are invisible to most experimental probes because of their symmetry. For example, the possible existence of superfluid stripes is not easily validated with linear optics, because the stripe alignment causes interlayer superconducting tunneling to vanish on average. Here we show that this frustration is removed in the nonlinear optical response. A giant terahertz third harmonic, characteristic of nonlinear Josephson tunneling, is observed in La1.885Ba0.115CuO4 above the transition temperature Tc = 13 kelvin and up to the charge-ordering temperature Tco = 55 kelvin. We model these results by hypothesizing the presence of a pair density wave condensate, in which nonlinear mixing of optically silent tunneling modes drives large dipole-carrying supercurrents.
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Affiliation(s)
- S Rajasekaran
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
| | - J Okamoto
- Centre for Optical Quantum Technologies and Institute for Laser Physics, University of Hamburg, Hamburg, Germany
| | - L Mathey
- Centre for Optical Quantum Technologies and Institute for Laser Physics, University of Hamburg, Hamburg, Germany
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - V Thampy
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, 11973 NY, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, 11973 NY, USA
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany. .,Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
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13
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Chen XM, Thampy V, Mazzoli C, Barbour AM, Miao H, Gu GD, Cao Y, Tranquada JM, Dean MPM, Wilkins SB. Remarkable Stability of Charge Density Wave Order in La_{1.875}Ba_{0.125}CuO_{4}. Phys Rev Lett 2016; 117:167001. [PMID: 27792368 DOI: 10.1103/physrevlett.117.167001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Indexed: 06/06/2023]
Abstract
The occurrence of charge-density-wave (CDW) order in underdoped cuprates is now well established, although the precise nature of the CDW and its relationship with superconductivity is not. Theoretical proposals include contrasting ideas such as that pairing may be driven by CDW fluctuations or that static CDWs may intertwine with a spatially modulated superconducting wave function. We test the dynamics of CDW order in La_{1.825}Ba_{0.125}CuO_{4} by using x-ray photon correlation spectroscopy at the CDW wave vector, detected resonantly at the Cu L_{3} edge. We find that the CDW domains are strikingly static, with no evidence of significant fluctuations up to 2 ¾ h. We discuss the implications of these results for some of the competing theories.
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Affiliation(s)
- X M Chen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - V Thampy
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - A M Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Y Cao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J M Tranquada
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S B Wilkins
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
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14
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Dean MPM, Cao Y, Liu X, Wall S, Zhu D, Mankowsky R, Thampy V, Chen XM, Vale JG, Casa D, Kim J, Said AH, Juhas P, Alonso-Mori R, Glownia JM, Robert A, Robinson J, Sikorski M, Song S, Kozina M, Lemke H, Patthey L, Owada S, Katayama T, Yabashi M, Tanaka Y, Togashi T, Liu J, Rayan Serrao C, Kim BJ, Huber L, Chang CL, McMorrow DF, Först M, Hill JP. Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4. Nat Mater 2016; 15:601-5. [PMID: 27159018 DOI: 10.1038/nmat4641] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/07/2016] [Indexed: 05/07/2023]
Abstract
Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity. Recently, photo-excitation has been used to induce similarly exotic states transiently. However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr2IrO4. We find that the non-equilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Néel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. The marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.
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Affiliation(s)
- M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Y Cao
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - X Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - S Wall
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - D Zhu
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - R Mankowsky
- Max Planck Institute for the Structure and Dynamics of Matter, D-22761 Hamburg, Germany
- Center for Free Electron Laser Science, D-22761 Hamburg, Germany
| | - V Thampy
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - X M Chen
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J G Vale
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - D Casa
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Jungho Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A H Said
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Juhas
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - R Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J M Glownia
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - A Robert
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J Robinson
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Sikorski
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Song
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Kozina
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - H Lemke
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - L Patthey
- SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - S Owada
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | - T Katayama
- Japan Synchrotron Radiation Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - M Yabashi
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | | | - T Togashi
- Japan Synchrotron Radiation Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - J Liu
- Department of Physics &Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C Rayan Serrao
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA
| | - B J Kim
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - L Huber
- Institute for Quantum Electronics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C-L Chang
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, NL 9747AG, The Netherlands
| | - D F McMorrow
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, D-22761 Hamburg, Germany
- Center for Free Electron Laser Science, D-22761 Hamburg, Germany
| | - J P Hill
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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15
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Ye Q, Gentile T, Anderson J, Broholm C, Chen W, DeLand Z, Erwin R, Fu C, Fuller J, Kirchhoff A, Rodriguez-Rivera J, Thampy V, Walker T, Watson S. Wide Angle Polarization Analysis with Neutron Spin Filters. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.phpro.2013.03.197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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16
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Thampy V, Kang J, Rodriguez-Rivera JA, Bao W, Savici AT, Hu J, Liu TJ, Qian B, Fobes D, Mao ZQ, Fu CB, Chen WC, Ye Q, Erwin RW, Gentile TR, Tesanovic Z, Broholm C. Friedel-like oscillations from interstitial iron in superconducting Fe(1+y)Te0.62Se0.38. Phys Rev Lett 2012; 108:107002. [PMID: 22463442 DOI: 10.1103/physrevlett.108.107002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Indexed: 05/31/2023]
Abstract
Using polarized and unpolarized neutron scattering, we show that interstitial Fe in superconducting Fe(1+y)Te(1-x)Se(x) induces a magnetic Friedel-like oscillation that diffracts at Q⊥=(1/2 0) and involves >50 neighboring Fe sites. The interstitial >2μ(B) moment is surrounded by compensating ferromagnetic four-spin clusters that may seed double stripe ordering in Fe(1+y)Te. A semimetallic five-band model with (1/2 1/2) Fermi surface nesting and fourfold symmetric superexchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.
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Affiliation(s)
- V Thampy
- Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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17
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Liu TJ, Hu J, Qian B, Fobes D, Mao ZQ, Bao W, Reehuis M, Kimber SAJ, Prokes K, Matas S, Argyriou DN, Hiess A, Rotaru A, Pham H, Spinu L, Qiu Y, Thampy V, Savici AT, Rodriguez JA, Broholm C. From (pi,0) magnetic order to superconductivity with (pi,pi) magnetic resonance in Fe(1.02)Te(1-x)Se(x). Nat Mater 2010; 9:716-20. [PMID: 20639892 DOI: 10.1038/nmat2800] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 06/08/2010] [Indexed: 05/25/2023]
Abstract
The iron chalcogenide Fe(1+y)(Te(1-x)Se(x)) is structurally the simplest of the Fe-based superconductors. Although the Fermi surface is similar to iron pnictides, the parent compound Fe(1+y)Te exhibits antiferromagnetic order with an in-plane magnetic wave vector (pi,0) (ref. 6). This contrasts the pnictide parent compounds where the magnetic order has an in-plane magnetic wave vector (pi,pi) that connects hole and electron parts of the Fermi surface. Despite these differences, both the pnictide and chalcogenide Fe superconductors exhibit a superconducting spin resonance around (pi,pi) (refs 9, 10, 11). A central question in this burgeoning field is therefore how (pi,pi) superconductivity can emerge from a (pi,0) magnetic instability. Here, we report that the magnetic soft mode evolving from the (pi,0)-type magnetic long-range order is associated with weak charge carrier localization. Bulk superconductivity occurs as magnetic correlations at (pi,0) are suppressed and the mode at (pi, pi) becomes dominant for x>0.29. Our results suggest a common magnetic origin for superconductivity in iron chalcogenide and pnictide superconductors.
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18
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Huang SX, Chien CL, Thampy V, Broholm C. Control of tetrahedral coordination and superconductivity in FeSe0.5Te0.5 thin films. Phys Rev Lett 2010; 104:217002. [PMID: 20867128 DOI: 10.1103/physrevlett.104.217002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Indexed: 05/29/2023]
Abstract
We demonstrate a close relationship between superconductivity and the dimensions of the Fe-Se(Te) tetrahedron in FeSe0.5Te0.5. This is done by exploiting thin film epitaxy, which provides controlled biaxial stress, both compressive and tensile, to distort the tetrahedron. The Se/Te height within the tetrahedron is found to be of crucial importance to superconductivity, in agreement with the scenario that (π, π) spin fluctuations promote superconductivity in Fe superconductors.
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Affiliation(s)
- S X Huang
- Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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