Article Dans Une Revue Nature Communications Année : 2025

Ultrafast charge-transfer-induced spin transition in cobalt-tungstate molecular photomagnets

Résumé

In materials exhibiting photoinduced phase transitions, and in which both charge transfer and spin transitions occur, there has long been a debate about which process drives the phase transition. Herein, we present experimental evidence supporting an optically charge-transfer-induced spin transition (CTIST) process, as demonstrated through femtosecond optical spectroscopy in two-dimensional cyanido-bridged cobalt-tungstate photomagnets. Optical and magnetic studies revealed that the photoexcitation of the ground low-temperature (LT) CoIIILS-WIV state leads to a photoinduced phase transition towards the CoIIHS-WV state, which is similar to the high temperature (HT) state. Ultrafast spectroscopy further indicates that this optical excitation of the intermetallic W-to-Co charge-transfer band produces a transient photoexcited (PE) CoIILS-WV state, which decays within 130 fs through a spin transition towards the CoIIHS-WV state. Here we show that the CTIST dynamics corresponds to the CoIIILS-WIV (LT) → CoIILS-WV (PE) → CoIIHS-WV (HT) sequence. The present work sheds a new light on understanding optical dynamics underlying the photoinduced phase transitions.

Fichier principal
Vignette du fichier
s41467-025-60401-4.pdf (1.94 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte
Licence

Dates et versions

hal-05158591 , version 1 (11-07-2025)

Licence

Identifiants

Citer

Kazuki Nakamura, Laurent Guérin, Gaël Privault, Koji Nakabayashi, Marius Hervé, et al.. Ultrafast charge-transfer-induced spin transition in cobalt-tungstate molecular photomagnets. Nature Communications, 2025, 16 (1), pp.5012. ⟨10.1038/s41467-025-60401-4⟩. ⟨hal-05158591⟩
202 Consultations
116 Téléchargements

Altmetric

Partager

  • More