Enthalpy relaxation and a.c. heat capacities

The experimental glass transition is, therefore, associated with a relaxing property - the enthalpy. The enthalpy/specific heat modes, in principle, couple to all phenomena which occur in the glass transition region. Enthalpy relaxation can be studied by applying a sinusoidal temperature pulse, much like an alternating electric field, which is applied to study dielectric relaxation. The specific heat is therefore treated as a frequency (of thermal field) dependent property. The traditional adiabatic technique cannot be applied because the time required for heat diffusion across the sample has to be short compared to the measurement time and the former is determined by the thermal diffusivity, which is low for most solids and is of the order of 10 cm s.  

7 marks the quenching of melt structure equilibrated at 7 -and does not mean that the structure of the resulting glass and that of the liquid at 7 are the same. 

KWW function with a / of 0.65 0.03 was found to fit well the imaginary parts of CpK ([Q,/r] ) at all temperatures. The peak relaxation frequencies were found to follow VTF law with a To of (128 5) K, very close to the Kauzmann temperature of 134 K. Such specific heat spectroscopy measurements, as described above have great potential for use, where other relaxation spectroscopic methods are either difficult or inconceivable. 

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