Frontiers in Physics (Sep 2022)

Faraday effect in CoPt-CaF2 nanogranular films with hard magnetic property for magnetic-field-free faraday devices

  • Nobukiyo Kobayashi,
  • Tadayoshi Iwasa,
  • Kenji Ikeda,
  • Ken-Ichi Arai

DOI
https://doi.org/10.3389/fphy.2022.940370
Journal volume & issue
Vol. 10

Abstract

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Magneto-optical Faraday devices, such as optical isolators, require a structure to apply a magnetic field to the incorporated magneto-optical material. The application of a magnetic field hinders the miniaturization and integration of these devices. Nanogranular films show Faraday rotation angles up to 40 times larger than Bi-YIG in the optical communication band (1,550 nm). Nanogranular films are submicron-to several-micrometer-thick and contribute to the miniaturization and integration of optical devices. Here, we introduce (Co-Pt)–(CaF2) nanogranular films exhibiting a magnetic-field-free magneto-optical Faraday effect, which are Co3Pt alloy that are hard magnets with residual magnetization. These nanogranular films exhibit the Faraday effect without requiring a magnetic field owing to their residual magnetization.

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