ac-calorimetry of (TMTSF)(2)PF6

摘要

We have searched for dynamic thermal effects in (TMTSF)(2)PF6 by measuring its specific heat with ac calorimetry. Near its spin-density-wave transition (T-c = 12 K), the magnitude of the specific heat is the same as that measured in quasi-static measurements, indicating that there are no kinetic contributions to the specific heat at these temperatures. The anomaly at T-c is consistent with the Ehrenfest relation estimate for a continuous phase transition. No anomalies are observed in a pellet of (TMTSF)(2)PF6 mixed with KBr at T-c or the expected "spin-density-wave glass" transition (T-g similar to 3.5 K), suggesting that residual disorder in the pellet freezes in a glassy state at T-c. (C) 2001 Elsevier Science Ltd. All rights reserved. References: 22