講演情報
[24a-1BB-2]Widefield Nitrogen-Vacancy Magnetometry of Pristine and Fe-implanted WS2
〇(D)Thitinun Gasosoth1, Yifei Wang1, Suvechhya Lamichhane2, Raman Kumar3, Tianlin Li2, Tom Delord3, Cory Cress4, Jose Fonesca Vega4, Xia Hong2, Toshu An1, Carlos Meriles3, Abdelghani Laraoui2 (1.JAIST, 2.U. Nebraska Lincoln, 3.CCNY, 4.U.S. Naval Res. Lab)
キーワード：
widefield NV magnetometry、WS2
The nitrogen-vacancy (NV) center in diamond has attracted considerable interest recently in magnetometry, due to its high magnetic field sensitivity at the nanometer scale. Widefield NV magnetic imaging platform has emerged as a tool to spatially map two-dimensional (2D) magnets [1]. The imaging modality is based on using a diamond chip doped with a dense layer of NV centers (few – 200 nm) near its surface, interrogated in a widefield optical microscope, to map the magnetic field of samples or devices placed in proximity [2]. Here, we use widefield NV magnetic microscopy to image the magnetic stray field produced from tungsten disulfide (WS2) flakes with a variable thickness (40 – 200 nm). The magnetization behavior of WS2 is still a mystery showing a weak ferromagnetism [2], that may extend its application from optoelectronics to spintronics. We study the magnetic properties of pristine and Fe-implanted WS2 2D flakes. The Fe-implantation is done over the mask with 125 µm holes and about 203.2 µm spacing to distinguish the effect of Fe on the magnetic properties of the WS2 flakes. The WS2 flakes are exfoliated and transferred to two diamond substrates doped with 10 nm and 150 nm thick NV layers respectively. Magnetic stray-field maps show distinct absorptive and dispersive-like magnetic patterns in the range of 1 – 20 mT at the edges of the WS2 flakes that depend strongly on the amplitude and orientation of the applied magnetic field along the NV axis. From magnetic field dependence measurements, we found that Fe reduces the overall magnetic stray field produced by the flakes, which may be explained by the local disorder induced by the implanted Fe atoms [3]. We finally model the spatially resolved magnetic maps of WS2 using COMSOL multiphysics magnetostatic simulation and confirm NV measurements [4].