Multi-frequency electron spin resonance apparatus in millimeter-wave range using a compact gyrotron

Authors

  • Yuya Ishikawa ⋅ JP Research Center for Development of Far-Infrared Region, University of Fukui, Japan

Abstract

Electron spin resonance (ESR) is widely used in science because it provides information on magnetic properties from a microscopic viewpoint. It is known that the ESR resolution improves as the light source becomes higher in frequency. The gyrotron is a kW-class high-power light source capable of oscillating in the THz-band. We have developed a highly sensitive magnetic resonance system by combining with a Force-Detection ESR (FDESR) system that measures minute magnetization changes. Here, we developed a new multi-frequency ESR system by combining a Compact Gyrotron (FU-CW CI) and the FDESR system with a variable temperature cryostat which can be used in the temperature range 5–300 K. Multi-frequency ESR signals of 1,1-diphenyl-2-picrylhydrazyl (DPPH) as standard samples were successfully detected at room temperature in the fundamental oscillation region of the gyrotron (108–206 GHz). The sensitivity was obtained to be in the order of 1012 spins/G from the ESR measurement of Cu(C4H4N2)(NO3)2 at room temperature. In addition, ESR signals of DPPH due to second harmonic waves (294–394 GHz) were successfully detected in the cryogenic region at 13 K. These results demonstrate the high compatibility of the gyrotron and FDESR system, as well as the ability to make comprehensive measurements in the region up to 0.4 THz. Recently, this magnetic resonance apparatus has been used to develop spintronics devices for thin-film antiferromagnetic materials. In the talk, examples of collaborative research using this light source will also be presented.

About the Speaker

Yuya Ishikawa, Research Center for Development of Far-Infrared Region, University of Fukui, Japan

Yuya Ishikawa is a senior assistant professor of the Research Center for Development of Far-Infrared Region, University of Fukui (FIR-UF). He obtained his Ph.D. in Advanced Interdisciplinary Science and Technology, University of Fukui in 2018. From 2018, he has been engaged in research and educational activities as an assistant professor at the Research Center for Development of Far-Infrared Region at the University of Fukui. He specializes in ultra-low temperature properties, low-dimensional magnetism and development of magnetic resonance systems. He received the Young Scientist Incentive Award from the Japan Society of Infrared Science and Technology in 2019 and the Society of Electron Spin Science and Technology (SEST) of Japan in 2022 (both in Japan).

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Article ID

SPP-2024-INV-1C-04

Section

Invited Presentations

Published

2024-07-02

How to Cite

[1]
Y Ishikawa, Multi-frequency electron spin resonance apparatus in millimeter-wave range using a compact gyrotron, Proceedings of the Samahang Pisika ng Pilipinas 42, SPP-2024-INV-1C-04 (2024). URL: https://proceedings.spp-online.org/article/view/SPP-2024-INV-1C-04.