Time-domain terahertz spectroscopy of spin state transition in [Fe(NH₂ − trz)₃]²⁺ spin crossover compounds

Benjamin Viquerat (1) , Jérôme Degert (1) , Marc Tondusson (1) , Eric Freysz (1) , Cindy Mauriac (2) , Jean-François Letard (2)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

We have measured the evolution of the THz spectrum of iron(II) spin crossover compounds within the low-spin/high-spin thermal hysteresis loop in the 0.6-6 THz frequency range. This study enabled to follow both the variations of the refractive optical index and absorption during the spin state transition. Marked absorptions centered ∼2 - 3 THz and ∼5 THz shifting with the spin state are revealed. Our work provides a means to store optically information and to read it out in the THz domain and also offers indications about the structural evolution occurring during the spin state transition.

Mots clés: High-speed optical techniques; Hysteresis; Iron compounds; Polymers; Refractive index; Visible spectra

Domaines: Matériaux

Benjamin Viquerat, Jérôme Degert, Marc Tondusson, Eric Freysz, Cindy Mauriac, et al.. Time-domain terahertz spectroscopy of spin state transition in [Fe(NH₂ − trz)₃]²⁺ spin crossover compounds. Applied Physics Letters, 2011, 99 (6), 061908 (3 p.). ⟨10.1063/1.3624600⟩. ⟨hal-00617181⟩