We measured the temperature and polarization dependences of the Raman scattering spectra of a quantum spin-liquid material, κ-(BEDT-TTF)2Cu2(CN)3 [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene], and an antiferromagnetic material, κ-(BEDT-TTF)2Cu[N(CN)2]Cl. The two materials generated distinctively different cross-polarization Raman scattering signals below 700 cm-1 , which were ascribed to two-magnon excitation. The center position of the spectral weight in κ-(BEDT-TTF)2Cu2(CN)3 is significantly lower than that in κ-(BEDT-TTF)2Cu[N(CN)2]Cl. The above spectral features give experimental evidence of spin frustration and can be explained in comparison with an anisotropic Heisenberg-model calculation for triangular spin systems.
ASJC Scopus subject areas
- Physics and Astronomy(all)