EFFECT OF MAGNETIC FLUCTUATIONS ON RAMAN-SCATTERING IN KAPPA-(BEDT-TTF)(2)CU(NCS)(2)

The temperature dependence of the intensity and frequency of two inten se features in the Raman spectrum of kappa-(BEDT-TTF)(2)Cu(NCS)(2) hav e been measured. The spectra were taken with a Fourier Raman spectrome ter equipped with an infrared laser. The two lines are due to a strong ly resonant nu(9)(A(g)) doublet, and a sharp line due to nu(60) (B-3g) . The frequencies of these modes are observed to soften below 80 K, in the temperature range where antiferromagnetic spin fluctuations have been observed with NMR, providing evidence of interactions between the phonons and the magnetism. [S0163-1829(98)50926-5].