GLASS-TRANSITION IN THE SPIN-DENSITY-WAVE PHASE OF (TMTSF)2PF6

We present the results of low frequency dielectric measurements and a detailed kinetic investigation of the specific heat anomaly in the spi n-density wave phase of (TMTSF)(2)PF6 in the temperature range between 2 and 4 K. The dielectric relaxation shows a critical slowing down to wards a ''static'' glass transition around 2 K. The jump in the specif ic heat in different controlled kinetic conditions shows all the chara cteristics of freezing in supercooled liquids. Both effects give direc t evidence of a glass transition in the spin-density wave ground state .