Effect of YIG nanoparticle size and clustering in proximity-induced magnetism in graphene/YIG composite probed with magnetoimpedance sensors: Towards improved functionality, sensitivity and proximity detection

Abstract

Proximity-induced magnetism (PIM) in graphene (Gr) adjacent to magnetic specimen has raised great fundamental interests. The subject is under debate and yet no application is proposed and granted. In this paper, toward accomplishment of fundamental facts, we first explore the effect of particle size and clustering in the PIM in Gr nanoplates (GNPs)/yttrium iron garnet (YIG) magnetic nanoparticle (MNP) composite. Microscopic analyzes suggest that fine MNPs distributed uniformly on the GNPs have higher saturation magnetization due to the PIM in Gr. We propose that such magnetic plates can thus be used to shield the stray field generated on the surface of magnetic sensors and play a role as a magnetic lens to prevent the field emanating outside the body of magnetic specimen. The GNPs/YIG composites are coated on a magnetic ribbon and proposed for application in magneto-impedance (MI) sensors. We show that such planar magnetic flakes enhance the MI response against the external applied magnetic field significantly. The suggested application can be furthermore developed toward bio-sensing and magnetic shielding in different magnetic sensors and devices.

Controlling Magnetization of Gr/Ni Composite for Application in High-Performance Magnetic Sensors

“…In this context, there are many reports on the surface modification of MI sensors by coating layers with different magnetization and conductivities. − ,− All articles have reported the increase in the MI ratio, and the physical origins are well-discussed through the decrease of surface roughness and the closed magnetic flux path − and magnetic exchange interactions between sensors and coated magnetic layers. , Also, some reports have used Gr-based materials and reported the better performances of their sensor device. ,,− For example, the vertical Gr sheets may redistribute the surface magnetic field, which is good for improving the transverse permeability, or the MnFe 2 O 4 –Gr oxide nanocomposite increased the MI ratio due to the suppressed physical motion of the MnFe 2 O 4 NPs on the Gr sheet, as well as the enhanced effective anisotropy of the sample . Very recently, we coated the (Gr nanoplates)/(yttrium iron garnet) (GNPs/YIG) composite on a magnetic ribbon and showed that the proximity-induced magnetism (PIM) in Gr adjacent to magnetic YIG influences the magnetization of the GNPs to make them a wholly magnetized plane . Such a magnetized plane can be mounted on the surface of ribbon MI sensors, and thereby the MI response is enhanced against the external applied magnetic field significantly.…”

“…56 Very recently, we coated the (Gr nanoplates)/(yttrium iron garnet) (GNPs/YIG) composite on a magnetic ribbon and showed that the proximity-induced magnetism (PIM) in Gr adjacent to magnetic YIG influences the magnetization of the GNPs to make them a wholly magnetized plane. 8 Such a magnetized plane can be mounted on the surface of ribbon MI sensors, and thereby the MI response is enhanced against the external applied magnetic field significantly. However, in the case of Gr/Ni composite, the difference in the magnetization of composites is related to the difference in the amount of magnetic particles in the composite and not only PIM.…”

“…In recent years, graphene (Gr), a two-dimensional (2D) hexagonal lattice of sp 2 hybridized carbon atoms, has attracted comprehensive research interest because of its fascinating electrical, mechanical, chemical, and optical properties and its potential application in next-generation electronics, , energy storage devices, − and composite-based materials. − Integration of Gr or the Gr family with various nanoparticles (NPs) allows the development of new nanocomposite materials with novel properties and highly promising applications in bioscience, − microwave elements, , sensors, etc …”

“…The environmental sensing ability and improving the magnetic field sensor performance are two aspects of this phenomenon. Enhancement of magnetic field sensitivity has been reported by coating layers with different magnetization and conductivities on the surface of MI sensors. ,− The physical origins are well-known through the magnetic proximity effect, decrease of surface roughness, and magnetic exchange interactions between sensors and coated magnetic layers. Also, surface modification of the ribbons has been reported intensively for detection of environmental elements through magnetic and nonmagnetic interactions with the environment …”

Giant magneto-impedance effect adjusted by electrolytic polishing and thinning of Co-based amorphous ribbons

“…The surface quality is a decisive factor in determining the GMI property. Based on these facts, plenty of works based on surface treatment have been done to further improve the GMI characteristics of amorphous materials, such as: surface treatment by using yttrium iron garnet magnetic nanoparticles [33], surface coating [30,34], surface ultrasound treatment [35], ion or ray irradiation [36,37], roughness modification [29], stress annealing [9,10], current annealing [8,11]. Besides, by immersing Fe and FeNi thin films into aromatic solvents, a prominent magnetic anisotropy variation has been observed [38].…”