1
|
Vera A, Zheng B, Yanez W, Yang K, Kim SY, Wang X, Kotsakidis JC, El-Sherif H, Krishnan G, Koch RJ, Bowen TA, Dong C, Wang Y, Wetherington M, Rotenberg E, Bassim N, Friedman AL, Wallace RM, Liu C, Samarth N, Crespi VH, Robinson JA. Large-Area Intercalated Two-Dimensional Pb/Graphene Heterostructure as a Platform for Generating Spin-Orbit Torque. ACS NANO 2024; 18:21985-21997. [PMID: 39102316 DOI: 10.1021/acsnano.4c04075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
A scalable platform to synthesize ultrathin heavy metals may enable high-efficiency charge-to-spin conversion for next-generation spintronics. Here, we report the synthesis of air-stable, epitaxially registered monolayer Pb underneath graphene on SiC (0001) by confinement heteroepitaxy (CHet). Diffraction, spectroscopy, and microscopy reveal that CHet-based Pb intercalation predominantly exhibits a mottled hexagonal superstructure due to an ordered network of Frenkel-Kontorova-like domain walls. The system's air stability enables ex situ spin torque ferromagnetic resonance (ST-FMR) measurements that demonstrate charge-to-spin conversion in graphene/Pb/ferromagnet heterostructures with a 1.5× increase in the effective field ratio compared to control samples.
Collapse
Affiliation(s)
- Alexander Vera
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Boyang Zheng
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Wilson Yanez
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kaijie Yang
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Seong Yeoul Kim
- Department of Materials Science and Engineering, The University of Texas at Dallas, Dallas ,Texas 75080, United States
| | - Xinglu Wang
- Department of Materials Science and Engineering, The University of Texas at Dallas, Dallas ,Texas 75080, United States
| | - Jimmy C Kotsakidis
- Laboratory for Physical Sciences, College Park, College Park ,Maryland 20740, United States
| | - Hesham El-Sherif
- Department of Materials Science and Engineering, McMaster University, Hamilton ,Ontario L8S 4L8, Canada
| | - Gopi Krishnan
- Department of Materials Science and Engineering, McMaster University, Hamilton ,Ontario L8S 4L8, Canada
| | - Roland J Koch
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - T Andrew Bowen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Chengye Dong
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Yuanxi Wang
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Maxwell Wetherington
- Materials Research Institute, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nabil Bassim
- Department of Materials Science and Engineering, McMaster University, Hamilton ,Ontario L8S 4L8, Canada
- Canadian Centre for Electron Microscopy, McMaster University, Hamilton ,Ontario L8S 4M1, Canada
| | - Adam L Friedman
- Laboratory for Physical Sciences, College Park, College Park ,Maryland 20740, United States
| | - Robert M Wallace
- Department of Materials Science and Engineering, The University of Texas at Dallas, Dallas ,Texas 75080, United States
| | - Chaoxing Liu
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Nitin Samarth
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| | - Vincent H Crespi
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Materials Research Institute, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Chemistry, The Pennsylvania State University, University Park ,Pennsylvania 18802, United States
| | - Joshua A Robinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for Nanoscale Science, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Materials Research Institute, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
- Department of Chemistry, The Pennsylvania State University, University Park ,Pennsylvania 18802, United States
- Center for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park ,Pennsylvania 16802, United States
| |
Collapse
|
2
|
Brozzesi S, Gori P, Koda DS, Bechstedt F, Pulci O. Thermodynamics and electronic structure of adsorbed and intercalated plumbene in graphene/hexagonal SiC heterostructures. Sci Rep 2024; 14:2947. [PMID: 38316818 PMCID: PMC10844374 DOI: 10.1038/s41598-024-53067-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 01/27/2024] [Indexed: 02/07/2024] Open
Abstract
Graphene-covered hexagonal SiC substrates have been frequently discussed to be appropriate starting points for epitaxial overlayers of Xenes, such as plumbene, or even their deposition as intercalates between graphene and SiC. Here, we investigate, within density functional theory, the plumbene deposition for various layer orderings and substrate terminations. By means of total energy studies we demonstrate the favorization of the intercalation versus the epitaxy for both C-terminated and Si-terminated 4H-SiC substrates. These results are explained in terms of chemical bonding and by means of layer-resolved projected band structures. Our results are compared with available experimental findings.
Collapse
Affiliation(s)
- Simone Brozzesi
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca 1, I-00133, Rome, Italy.
| | - Paola Gori
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via della Vasca Navale 79, I-00146, Rome, Italy.
| | - Daniel S Koda
- Lawrence Livermore National Laboratory, 7000 East Ave, L-367, Livermore, CA, 94551, USA
| | - Friedhelm Bechstedt
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743, Jena, Germany
| | - Olivia Pulci
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca 1, I-00133, Rome, Italy
| |
Collapse
|
3
|
Yang D, Ma F, Bian X, Xia Q, Xu K, Hu T. The growth of epitaxial graphene on SiC and its metal intercalation: a review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:173003. [PMID: 38237180 DOI: 10.1088/1361-648x/ad201a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 01/18/2024] [Indexed: 02/02/2024]
Abstract
High-quality epitaxial graphene (EG) on SiC is crucial to high-performance electronic devices due to the good compatibility with Si-based semiconductor technology. Metal intercalation has been considered as a basic technology to modify EG on SiC. In the past ten years, there have been extensive research activities on the structural evolution during EG fabrication, characterization of the atomic structure and electronic states of EG, optimization of the fabrication process, as well as modification of EG by metal intercalation. In this perspective, the developments and breakthroughs in recent years are summarized and future expectations are discussed. A good understanding of the growth mechanism of EG and subsequent metal intercalation effects is fundamentally important.
Collapse
Affiliation(s)
- Dong Yang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- Department of Physics, School of Biomedical Information and Engineering, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Fei Ma
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
| | - Xianglong Bian
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Qianfeng Xia
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Kewei Xu
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
| | - Tingwei Hu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
| |
Collapse
|
4
|
Han Y, Chen S, Hall J, Roberts S, Kolmer M, Evans JW, Tringides MC. Degeneracy in Intercalated Pb Phases under Buffer-Layer Graphene on SiC(0001) and Diffuse Moiré Spots in Surface Diffraction. J Phys Chem Lett 2023; 14:7053-7058. [PMID: 37526312 DOI: 10.1021/acs.jpclett.3c01688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
First-principles density functional theory (DFT) is used to analyze the stability of Pb intercalated phases under buffer layer graphene on SiC(0001) as a function of the supercell size, Pb coverage, and degree of Pb ordering. By comparing the chemical potentials of such two-dimensional Pb structures, we find that there is a family of structurally distinct thermodynamically preferred Pb subsurface configurations with minute stability differences. These differences are comparable to the thermal energies at about 450 °C, where the Pb intercalated phases are grown. High-resolution surface-diffraction experiments using Spot Profile Analysis Low-Energy Electron Diffraction (SPA-LEED) confirm this high degree of degeneracy of the Pb intercalated phases from broad, low-intensity moiré spots observed exclusively from intercalated Pb. The low intensity of the moiré spots implies the coexistence of structurally different subsurface Pb phases.
Collapse
Affiliation(s)
- Yong Han
- Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Shen Chen
- Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Joseph Hall
- Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Samuel Roberts
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Marek Kolmer
- Ames National Laboratory, Ames, Iowa 50011, United States
| | - James W Evans
- Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Michael C Tringides
- Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| |
Collapse
|
5
|
Ghosal C, Gruschwitz M, Koch J, Gemming S, Tegenkamp C. Proximity-Induced Gap Opening by Twisted Plumbene in Epitaxial Graphene. PHYSICAL REVIEW LETTERS 2022; 129:116802. [PMID: 36154419 DOI: 10.1103/physrevlett.129.116802] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 08/17/2022] [Indexed: 06/16/2023]
Abstract
Besides graphene, further honeycomb 2D structures were successfully synthesized on various surfaces. However, almost flat plumbene hosting topologically protected edge states could not yet be realized. In this Letter, we investigated the intercalation of Pb on buffer layers on SiC(0001). Thereby, suspended and charge neutral graphene emerged, and the intercalated Pb formed plumbene honeycomb lattices, which are rotated by ±7.5° with respect to graphene. Along with this twist, a proximity-induced modulation of the hopping parameter in graphene opens a band gap of around 30 meV at the Fermi energy, giving rise to a metal-insulator transition. Moreover, the edges of the intercalated plumbene layers revealed edge states within the gap of the conduction bands at around 1 eV as expected for charge neutral plumbene.
Collapse
Affiliation(s)
- Chitran Ghosal
- Institut für Physik,Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Markus Gruschwitz
- Institut für Physik,Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Julian Koch
- Institut für Physik,Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Sibylle Gemming
- Institut für Physik,Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Christoph Tegenkamp
- Institut für Physik,Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| |
Collapse
|