scholarly journals Probing magnetism in 2D materials at the nanoscale with single-spin microscopy

Science ◽  
2019 ◽  
Vol 364 (6444) ◽  
pp. 973-976 ◽  
Author(s):  
L. Thiel ◽  
Z. Wang ◽  
M. A. Tschudin ◽  
D. Rohner ◽  
I. Gutiérrez-Lezama ◽  
...  
Keyword(s):  
2D Materials ◽  
Nitrogen Vacancy ◽  
Two Dimensional ◽  
Magnetic Domains ◽  
Structural Modifications ◽  
Single Spin ◽  
Number Of Layers ◽  
Nitrogen Vacancy Centers ◽  
Localized Defects ◽  
Widespread Interest

The discovery of ferromagnetism in two-dimensional (2D) van der Waals (vdW) crystals has generated widespread interest. Making further progress in this area requires quantitative knowledge of the magnetic properties of vdW magnets at the nanoscale. We used scanning single-spin magnetometry based on diamond nitrogen-vacancy centers to image the magnetization, localized defects, and magnetic domains of atomically thin crystals of the vdW magnet chromium(III) iodide (CrI3). We determined the magnetization of CrI3monolayers to be ≈16 Bohr magnetons per square nanometer, with comparable values in samples with odd numbers of layers; however, the magnetization vanishes when the number of layers is even. We also found that structural modifications can induce switching between ferromagnetic and antiferromagnetic interlayer ordering. These results demonstrate the benefit of using single-spin scanning magnetometry to study the magnetism of 2D vdW magnets.

scholarly journals Magnetic domains and domain wall pinning in two-dimensional ferromagnets revealed by nanoscale imaging

2020 ◽  
Author(s):  
Qi-Chao Sun ◽  
Tiancheng Song ◽  
Eric Anderson ◽  
Tetyana Shalomayeva ◽  
Johannes Förster ◽  
...  
Keyword(s):  
Domain Structure ◽  
Spatial Resolution ◽  
Magnetic Domain ◽  
Magnetic Domain Structure ◽  
Nitrogen Vacancy ◽  
Two Dimensional ◽  
Magnetic Domains ◽  
Pinning Effect ◽  
Nitrogen Vacancy Center ◽  
Vacancy Center

Abstract Magnetic-domain structure and dynamics play an important role in understanding and controlling the magnetic properties of two-dimensional magnets, which are of interest to both fundamental studies and applications. However, the probe methods based on the spin-dependent optical permeability and electrical conductivity can neither provide quantitative information of the magnetization nor achieve nanoscale spatial resolution. These capabilities are essential to image and understand the rich properties of magnetic domains. Here, we employ cryogenic scanning magnetometry using a single-electron spin of a nitrogen-vacancy center in a diamond probe to unambiguously prove the existence of magnetic domains and study their dynamics in atomically thin CrBr3. The high spatial resolution of this technique enables imaging of magnetic domains and allows to resolve domain walls pinned by defects. By controlling the magnetic domain evolution as a function of magnetic field, we find that the pinning effect is a dominant coercivity mechanism with a saturation magnetization of about 26μB/nm2 for bilayer CrBr3. The magnetic-domain structure and pinning-effect dominated domain reversal process are verified by micromagnetic simulation. Our work highlights scanning nitrogen-vacancy center magnetometry as a quantitative probe to explore two-dimensional magnetism at the nanoscale.

Thin-Shell Thickness of Two-Dimensional Materials

2015 ◽  
Vol 82 (12) ◽  
Author(s):  
Enlai Gao ◽  
Zhiping Xu
Keyword(s):  
Thin Shell ◽  
Shell Thickness ◽  
2D Materials ◽  
Wide Spectrum ◽  
Elastic Shell ◽  
Bending Stiffness ◽  
Interlayer Distance ◽  
Structural Deformation ◽  
Two Dimensional ◽  
Number Of Layers

In applying the elastic shell models to monolayer or few-layer two-dimensional (2D) materials, an effective thickness has to be defined to capture their tensile and out-of-plane mechanical behaviors. This thin-shell thickness differs from the interlayer distance of their layer-by-layer assembly in the bulk and is directly related to the Föppl–von Karman number that characterizes the mechanism of nonlinear structural deformation. In this work, we assess such a definition for a wide spectrum of 2D crystals of current interest. Based on first-principles calculations, we report that the discrepancy between the thin-shell thickness and interlayer distance is weakened for 2D materials with lower tensile stiffness, higher bending stiffness, or more number of atomic layers. For multilayer assembly of 2D materials, the tensile and bending stiffness have different scaling relations with the number of layers, and the thin-shell thickness per layer approaches the interlayer distance as the number of layers increases. These findings lay the ground for constructing continuum models of 2D materials with both tensile and bending deformation.

scholarly journals Magnetic domains and domain wall pinning in atomically thin CrBr3 revealed by nanoscale imaging

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qi-Chao Sun ◽  
Tiancheng Song ◽  
Eric Anderson ◽  
Andreas Brunner ◽  
Johannes Förster ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Quantitative Information ◽  
Nitrogen Vacancy ◽  
Two Dimensional ◽  
Magnetic Domains ◽  
Nitrogen Vacancy Center ◽  
The Rich ◽  
Vacancy Center

AbstractThe emergence of atomically thin van der Waals magnets provides a new platform for the studies of two-dimensional magnetism and its applications. However, the widely used measurement methods in recent studies cannot provide quantitative information of the magnetization nor achieve nanoscale spatial resolution. These capabilities are essential to explore the rich properties of magnetic domains and spin textures. Here, we employ cryogenic scanning magnetometry using a single-electron spin of a nitrogen-vacancy center in a diamond probe to unambiguously prove the existence of magnetic domains and study their dynamics in atomically thin CrBr3. By controlling the magnetic domain evolution as a function of magnetic field, we find that the pinning effect is a dominant coercivity mechanism and determine the magnetization of a CrBr3 bilayer to be about 26 Bohr magnetons per square nanometer. The high spatial resolution of this technique enables imaging of magnetic domains and allows to locate the sites of defects that pin the domain walls and nucleate the reverse domains. Our work highlights scanning nitrogen-vacancy center magnetometry as a quantitative probe to explore nanoscale features in two-dimensional magnets.

Co-planar two-dimensional Metal-Insulator-Semiconductor Capacitor: Numerical study of the device electrostatics.

2017 ◽  
Author(s):  
Varun Bheemireddy
Keyword(s):  
Space Charge ◽  
High Performance ◽  
Numerical Study ◽  
2D Materials ◽  
Space Charge Density ◽  
Two Dimensional ◽  
Short Channel ◽  
Metal Insulator ◽  
Metal Insulator Semiconductor ◽  
New Family

The two-dimensional(2D) materials are highly promising candidates to realise elegant and e cient transistor. In the present letter, we conjecture a novel co-planar metal-insulator-semiconductor(MIS) device(capacitor) completely based on lateral 2D materials architecture and perform numerical study of the capacitor with a particular emphasis on its di erences with the conventional 3D MIS electrostatics. The space-charge density features a long charge-tail extending into the bulk of the semiconductor as opposed to the rapid decay in 3D capacitor. Equivalently, total space-charge and semiconductor capacitance densities are atleast an order of magnitude more in 2D semiconductor. In contrast to the bulk capacitor, expansion of maximum depletion width in 2D semiconductor is observed with increasing doping concentration due to lower electrostatic screening. The heuristic approach of performance analysis(2D vs 3D) for digital-logic transistor suggest higher ON-OFF current ratio in the long-channel limit even without third dimension and considerable room to maximise the performance of short-channel transistor. The present results could potentially trigger the exploration of new family of co-planar at transistors that could play a signi significant role in the future low-power and/or high performance electronics.<br>

Recent Advances and Need of Green Synthesis in Two-Dimensional Materials for Energy Conversion and Storage Applications

2021 ◽  
Vol 16 ◽  
Author(s):  
Joice Sophia Ponraj ◽  
Muniraj Vignesh Narayanan ◽  
Ranjith Kumar Dharman ◽  
Valanarasu Santiyagu ◽  
Ramalingam Gopal ◽  
...  
Keyword(s):  
Energy Storage ◽  
Green Synthesis ◽  
2D Materials ◽  
Synthesis Method ◽  
Energy Storage And Conversion ◽  
Two Dimensional ◽  
Severe Problem ◽  
Energy Conversion And Storage ◽  
Energy Application ◽  
The Impact

: Increasing energy crisis across the globe requires immediate solutions. Two-dimensional (2D) materials are in great significance because of its application in energy storage and conversion devices but the production process significantly impacts the environment thereby posing a severe problem in the field of pollution control. Green synthesis method provides an eminent way of reduction in pollutants. This article reviews the importance of green synthesis in the energy application sector. The focus of 2D materials like graphene, MoS2, VS2 in energy storage and conversion devices are emphasized based on supporting recent reports. The emerging Li-ion batteries are widely reviewed along with their promising alternatives like Zn, Na, Mg batteries and are featured in detail. The impact of green methods in the energy application field are outlined. Moreover, future outlook in the energy sector is envisioned by proposing an increase in 2D elemental materials research.

Two-dimensional topological insulators exfoliated from Na3Bi-like Dirac semimetals

2021 ◽  
Author(s):  
Xiaoqiu Guo ◽  
Ruixin Yu ◽  
Jingwen Jiang ◽  
Zhuang Ma ◽  
Xiuwen Zhang
Keyword(s):  
Physical Properties ◽  
Epitaxial Growth ◽  
Topological Insulators ◽  
2D Materials ◽  
Van Der Waals ◽  
Two Dimensional ◽  
Dirac Semimetals

Topological insulation is widely predicted in two-dimensional (2D) materials realized by epitaxial growth or van der Waals (vdW) exfoliation. Such 2D topological insulators (TI’s) host many interesting physical properties such...

Combined Healing and Doping of Transition Metal Dichalcogenides Through Molecular Functionalization

2021 ◽  
Author(s):  
Sai Manoj Gali ◽  
David Beljonne
Keyword(s):  
Transition Metal ◽  
Charge Transport ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
Metal Dichalcogenides

Transition Metal Dichalcogenides (TMDCs) are emerging as promising two-dimensional (2D) materials. Yet, TMDCs are prone to inherent defects such as chalcogen vacancies, which are detrimental to charge transport. Passivation of...

scholarly journals A robust fiber-based quantum thermometer coupled with nitrogen-vacancy centers

2021 ◽  
Vol 92 (4) ◽  
pp. 044904
Author(s):  
Shao-Chun Zhang ◽  
Yang Dong ◽  
Bo Du ◽  
Hao-Bin Lin ◽  
Shen Li ◽  
...  
Keyword(s):  
Nitrogen Vacancy ◽  
Nitrogen Vacancy Centers
Sign in / Sign up

Export Citation Format

Share Document