Room-temperature magnetoresistance in Ni78Fe22/C8-BTBT/Ni78Fe22 nanojunctions fabricated from magnetic thin-film edges using a novel technique

Matsuzaka, Mizuki; Sasaki, Yoshi N.; Hayashi, Kyohei; Misawa, Takahiro; Komine, Takashi; Akutagawa, Tomoyuki; Fujioka, M.; Nishii, Junji; Kaiju, Hideo

doi:10.1039/d2na00442a

Cited by 3 publications

(1 citation statement)

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“…In particular, NiFe (Permalloy) is a material with excellent properties such as high relative permeability, low coercivity, and near-zero magnetostriction, and it is widely used in fields such as magnetic shielding and magnetic sensors. In recent years, magnetic tunnel junctions (MTJs) and spin valves (SVs), stacks of magnetic layers with insulators, metal layers, or molecular materials, have attracted significant attention for application in highly sensitive magnetic sensors and magnetic memory (storage) devices that leverage their unique magnetoresistance and magnetocapacitance effects. − However, the formation of microelectrodes on these magnetic devices requires not only the precise fabrication of electrodes with nanoscale precision but also extra work to remove the oxide layer of a few nm formed on the NiFe surface by additional dry/wet etching or annealing processes . Therefore, for the formation of micro- and nano-sized spintronics devices, it is important to have a technology to easily fabricate microelectrodes that exhibit good conductivity at the desired position on the device with nanoscale precision.…”

Section: Introductionmentioning

confidence: 99%

Site-Specific Synthesis of Conductive Graphitic Nanomaterials on a NiFe Thin Film by Localized Laser Irradiation

Fujiwara,

Daikokuya,

Mirokuin

et al. 2023

ACS Appl. Nano Mater.

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We report on a facile and low-cost method for the site-specific fabrication of carbon microelectrodes on a NiFe thin film-coated substrate by laser-induced heating of the NiFe layer immersed in ethanol. Raman spectroscopy analysis of the carbon materials synthesized confirms that, after optimization of the laser heating conditions (in terms of laser power, irradiation time, and the number of radiation bursts), the G band peak in the Raman spectra is increased and sharpened and the D/G ratio improved. In addition, from the scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements, we find that the laser-irradiated site is rich in particle-like graphitic nanomaterials with nano-sized grains that are densely distributed on the NiFe substrate. Furthermore, conductive atomic force microscopy measurements show that optimized irradiation conditions enable not only the localized formation of low-D/G-Raman-peak-ratio graphitic nanomaterials with good conductivity but also an increase of the current flow in the laser-irradiated area, reaching current values much higher than that of the bare NiFe thin film. From these results, we conjecture that nanocrystalline-like graphitic nanomaterials with fewer structural defects and good conductivity are synthesized in the laser-irradiated area. This laser-induced graphitic nanomaterials synthesis method can potentially be adapted to directly and locally form carbon microelectrodes on magnetic thin films, offering unique advantages for the development of micromagnetic devices.

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Section: Introductionmentioning

confidence: 99%

Site-Specific Synthesis of Conductive Graphitic Nanomaterials on a NiFe Thin Film by Localized Laser Irradiation

Fujiwara,

Daikokuya,

Mirokuin

et al. 2023

ACS Appl. Nano Mater.

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Room-Temperature Magnetoresistance in Nanojunctions Consisting of C8-BTBT Molecules Sandwiched Between Two Magnetic Thin-Film Edges

Matsuzaka,

Sasaki,

Hayashi

et al. 2023

2023 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers)

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Advances in Organic Multiferroic Junctions

Borca

2024

Coatings

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Typically, organic multiferroic junctions (OMFJs) are formed of an organic ferroelectric layer sandwiched between two ferromagnetic electrodes. The main scientific interest in OMFJs focuses on the magnetoresistive properties of the magnetic spin valve combined with the electroresistive properties associated with the ferroelectric junction. In consequence, memristive properties that couple magnetoelectric functionalities, which are one of the most active fields of research in material sciences, are opening a large spectrum of technological applications from nonvolatile memory to elements in logic circuits, sensing devices, energy harvesting and biological synapsis models in the emerging area of neuromorphic computing. The realization of these multifunctional electronic elements using organic materials is presenting various advantages related to their low-cost, versatile synthesis and low power consumption functioning for sustainable electronics; green disintegration for transient electronics; and flexibility, light weight and/or biocompatibility for flexible electronics. The purpose of this review is to address the advancement of all OMFJs including not only the achievements in the charge and spin transport through OMFJs together with the effects of electroresistance and magnetoresistance but also the challenges and ways to overcome them for the most used materials for OMFJs.

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Room-temperature magnetoresistance in Ni₇₈Fe₂₂/C8-BTBT/Ni₇₈Fe₂₂ nanojunctions fabricated from magnetic thin-film edges using a novel technique

Abstract: The paper presents room-temperature magnetoresistance in molecular spintronic nanodevices fabricated using magnetic thin-film edges.

Cited by 3 publications

References 64 publications

Site-Specific Synthesis of Conductive Graphitic Nanomaterials on a NiFe Thin Film by Localized Laser Irradiation

Site-Specific Synthesis of Conductive Graphitic Nanomaterials on a NiFe Thin Film by Localized Laser Irradiation

Room-Temperature Magnetoresistance in Nanojunctions Consisting of C8-BTBT Molecules Sandwiched Between Two Magnetic Thin-Film Edges

Advances in Organic Multiferroic Junctions

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