THE SPECIFIC-HEAT STUDY OF CHARGE-DENSITY-WAVE PHASE-TRANSITIONS FOR THE BLUE BRONZE TL0.3MOO3

The specific heat of the blue bronze Tl0.3MoO3 is measured using an ad iabatic continuous heating method from 100 to 200 K. A specific heat a nomaly is observed at 172.3 K. The specific heat jump, and enthalpy an d entropy changes associated with the CDW phase transition are estimat ed. The results suggest that the phase transition is of second order a nd that the lattice plays an important role in thermodynamics in this system, by analogy with the behaviour of its isostructural compound K0 .3MoO3. The mean-field theory seems not to be adequate for describing the CDW phase transition in this compound.