Quantitative microwave impedance microscopy with effective medium approximations

Two-dimensional heterostructures composed of layers with slightly different lattice vectors exhibit new periodic structure known as moiré lattices, which, in turn, can support novel correlated and topological phenomena. Moreover, moiré superstructures can emerge from multiple misaligned moiré lattices or inhomogeneous strain distributions, offering additional degrees of freedom in tailoring electronic structure. High-resolution imaging of the moiré lattices and superstructures is critical for understanding the emerging physics. Here, we report the imaging of moiré lattices and superstructures in graphene-based samples under ambient conditions using an ultrahigh-resolution implementation of scanning microwave impedance microscopy. Although the probe tip has a gross radius of ~100 nm, spatial resolution better than 5 nm is achieved, which allows direct visualization of the structural details in moiré lattices and the composite super-moiré. We also demonstrate artificial synthesis of novel superstructures, including the Kagome moiré arising from the interplay between different layers.

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“…1G and figs. S6 and S7), which is superior to previous sMIM reports (32,(52)(53)(54)(55)(56)(57)(58)(59).…”

Section: Ultrahigh-resolution Scannning Microwave Impedance Microscopycontrasting

confidence: 52%

Ultrahigh-resolution scanning microwave impedance microscopy of moiré lattices and superstructures

et al. 2020

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“…There are also some relatively newly developed techniques, including scanning microwave impedance microscopy and scanning impedance microscopy (SIM) . SMIM is primarily used in semiconductor industry to quantify permittivity, capacitance, resistance, and dopant concentration and locate the imperfections or electrical inhomogeneity . SIM measures the local AC transport behavior.…”

Section: Scanning Probe Microscopy Techniquesmentioning

confidence: 99%

Probing of Local Multifield Coupling Phenomena of Advanced Materials by Scanning Probe Microscopy Techniques

Zeng

2018

Advanced Materials

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The characterization of the local multifield coupling phenomenon (MCP) in various functional/structural materials by using scanning probe microscopy (SPM)-based techniques is comprehensively reviewed. Understanding MCP has great scientific and engineering significance in materials science and engineering, as in many practical applications, materials and devices are operated under a combination of multiple physical fields, such as electric, magnetic, optical, chemical and force fields, and working environments, such as different atmospheres, large temperature fluctuations, humidity, or acidic space. The materials' responses to the synergetic effects of the multifield (physical and environmental) determine the functionalities, performance, lifetime of the materials, and even the devices' manufacturing. SPM techniques are effective and powerful tools to characterize the local effects of MCP. Here, an introduction of the local MCP, the descriptions of several important SPM techniques, especially the electrical, mechanical, chemical, and optical related techniques, and the applications of SPM techniques to investigate the local phenomena and mechanisms in oxide materials, energy materials, biomaterials, and supramolecular materials are covered. Finally, an outlook of the MCP and SPM techniques in materials research is discussed.Multifield Coupling temperature, moisture, and atmosphere. The studies of multifield coupling phenomena (MCP) are important for functional and structural materials because they are often operated under several external stimuli simultaneously in real applications. In the area of multifield coupling, a group of researchers have dedicated to the computational and modeling works in order to explain

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“…In Ref. 68, the authors created a quantification scheme extracting sample conductivity and permittivity from admittance with only the use of the capacitive calibration die provided by the instrument using simulations and MIM measurements. The prediction was verified with a sample of polytetrafluoroethylene (PTFE).…”

Section: Quantitative Measurements Of Nanoscale Permittivity and Condmentioning

confidence: 99%

Developments and Recent Progresses in Microwave Impedance Microscope

et al. 2020

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Microwave impedance microscope (MIM) is a near-field microwave technology which has low emission energy and can detect samples without any damages. It has numerous advantages, which can appreciably suppress the common-mode signal as the sensing probe separates from the excitation electrode, and it is an effective device to represent electrical properties with high spatial resolution. This article reviews the major theories of MIM in detail which involve basic principles and instrument configuration. Besides, this paper summarizes the improvement of MIM properties, and its cutting-edge applications in quantitative measurements of nanoscale permittivity and conductivity, capacitance variation, and electronic inhomogeneity. The relevant implementations in recent literature and prospects of MIM based on the current requirements are discussed. Limitations and advantages of MIM are also highlighted and surveyed to raise awareness for more research into the existing near-field microwave microscopy. This review on the ongoing progress and future perspectives of MIM technology aims to provide a reference for the electronic and microwave measurement community.

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Quantitative microwave impedance microscopy with effective medium approximations

Cited by 5 publications

References 20 publications

Ultrahigh-resolution scanning microwave impedance microscopy of moiré lattices and superstructures

Ultrahigh-resolution scanning microwave impedance microscopy of moiré lattices and superstructures

Probing of Local Multifield Coupling Phenomena of Advanced Materials by Scanning Probe Microscopy Techniques

Developments and Recent Progresses in Microwave Impedance Microscope

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