ELECTRONIC-STRUCTURE OF INSULATING SALTS OF THE KAPPA-(BEDT-TTF)(2)X FAMILY STUDIED BY LOW-TEMPERATURE SPECIFIC-HEAT MEASUREMENTS - COMMENT

Recently reported specific-heat measurements by Nakazawa and Kanoda be tween 20 and 50 K show no evidence for an expected antiferromagnetic o rdering transition in the quasi-two-dimensional (2D) molecular conduct or kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl [Y. Nakazawa and K. Kanoda, Phys. Rev. B 53, R8875 (1996)]. Although the absence of an observable trans ition was taken as evidence for 2D short-range ordering at elevated te mperatures, even a small increase in pressure from the application of the grease used to mount the sample would shift this magnetic transiti on below 20 K. In their paper, Nakazawa and Kanoda erroneously assume that pressure-induced effects can be ruled out by the magnetic-field i ndependence of the low-temperature specific heat below 3 K. In this Co mment, we explain why this assumption is invalid. We conclude that spe cific-heat measurements in the intermediate temperature range of 3-20 K are needed before the absence of a discernible magnetic and/or press ure-induced phase transitions can be asserted.