Type-II-like ultrafast demagnetization behavior in NiCo2O4 thin films

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Takahashi, Ryunosuke, Yamada, Kaede, Singh, Harjinder, Watanabe, Kanata, Igarashi, Junta, Hohlfeld, Julius, Gorchon, Jon, Malinowski, Gregory, Kan, Daisuke, Shimakawa, Yuichi, Ishibashi, Takayuki, Mangin, Stephane, Wadati, Hiroki
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911606275833856
author Takahashi, Ryunosuke
Yamada, Kaede
Singh, Harjinder
Watanabe, Kanata
Igarashi, Junta
Hohlfeld, Julius
Gorchon, Jon
Malinowski, Gregory
Kan, Daisuke
Shimakawa, Yuichi
Ishibashi, Takayuki
Mangin, Stephane
Wadati, Hiroki
author_facet Takahashi, Ryunosuke
Yamada, Kaede
Singh, Harjinder
Watanabe, Kanata
Igarashi, Junta
Hohlfeld, Julius
Gorchon, Jon
Malinowski, Gregory
Kan, Daisuke
Shimakawa, Yuichi
Ishibashi, Takayuki
Mangin, Stephane
Wadati, Hiroki
contents Rare-earth-ferrimagnetic oxides are emerging as attractive platforms for investigating ultrafast spin dynamics. Here, we study the photoinduced magnetization dynamics of epitaxial NiCo2O4 (NCO) thin films by time-resolved magneto-optical Faraday effect using two independent pump-probe configurations: 1030/515 nm and 800/400 nm. In both measurements, photoexcitation induces an immediate reduction of the magneto-optical signal within the experimental time resolution, followed by a reproducible slower demagnetization component with a characteristic timescale of approximately 5-6 ps and a subsequent recovery on the ~100 ps timescale. Importantly, this picosecond demagnetization component is observed consistently across the two experimental configurations and excitation wavelengths, demonstrating that it is an intrinsic feature of the ultrafast magnetic response of NCO thin films. Because the earliest-time dip may contain a transient optical contribution, we describe the overall response as type-II-like, rather than assigning a definitive textbook type-II classification solely on the basis of the sub-resolution signal. These results establish a robust two-step ultrafast demagnetization behavior in NCO and highlight rare-earth-free oxide ferrimagnets as promising systems for exploring Mult sublattice spin dynamics on ultrafast timescales.
format Preprint
id arxiv_https___arxiv_org_abs_2604_17916
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Type-II-like ultrafast demagnetization behavior in NiCo2O4 thin films
Takahashi, Ryunosuke
Yamada, Kaede
Singh, Harjinder
Watanabe, Kanata
Igarashi, Junta
Hohlfeld, Julius
Gorchon, Jon
Malinowski, Gregory
Kan, Daisuke
Shimakawa, Yuichi
Ishibashi, Takayuki
Mangin, Stephane
Wadati, Hiroki
Materials Science
Rare-earth-ferrimagnetic oxides are emerging as attractive platforms for investigating ultrafast spin dynamics. Here, we study the photoinduced magnetization dynamics of epitaxial NiCo2O4 (NCO) thin films by time-resolved magneto-optical Faraday effect using two independent pump-probe configurations: 1030/515 nm and 800/400 nm. In both measurements, photoexcitation induces an immediate reduction of the magneto-optical signal within the experimental time resolution, followed by a reproducible slower demagnetization component with a characteristic timescale of approximately 5-6 ps and a subsequent recovery on the ~100 ps timescale. Importantly, this picosecond demagnetization component is observed consistently across the two experimental configurations and excitation wavelengths, demonstrating that it is an intrinsic feature of the ultrafast magnetic response of NCO thin films. Because the earliest-time dip may contain a transient optical contribution, we describe the overall response as type-II-like, rather than assigning a definitive textbook type-II classification solely on the basis of the sub-resolution signal. These results establish a robust two-step ultrafast demagnetization behavior in NCO and highlight rare-earth-free oxide ferrimagnets as promising systems for exploring Mult sublattice spin dynamics on ultrafast timescales.
title Type-II-like ultrafast demagnetization behavior in NiCo2O4 thin films
topic Materials Science
url https://arxiv.org/abs/2604.17916