MEASUREMENTS OF ACCURATE SPECIFIC-HEATS OF METALLIC GLASSES BY DIFFERENTIAL SCANNING CALORIMETRY (DSC) .1. ANALYSIS OF THEORETICAL PRINCIPLES AND ACCURACIES OF SUGGESTED MEASUREMENT PROCEDURES

Two techniques for DSC specific heat measurements have been tested. They are, (1) the continual heating two run technique by means of a Perkin-Elmer DSC7 device and the scanning (differential) method, and (2) the programmed stepwise heating two-run technique by means of a Setaram DSC111 device and the integral (enthalpic) method. The correctness of the theoretical principles and the accuracies of obtained experimental data on metallic ribbons from 300 to 1054 K are analyzed. The measurements on Fe73Co12B15 and Co67Cr7Fe4Si8B14 metallic glasses are given as an example. The sensitivity is better than 0.05 J g-1 at-1 K-1, the maximal dispersion of data is +/- 1.2%. The main sources of irreproducibilities in measured c(p)(T) dependencies are the internal thermodynamic properties of the samples.