The Dependences of Specific Heat of α-Al₂O₃ on the Testing Conditions of Modulated DSC

The dependences of specific heat (C_p) of α-Al₂O₃ on the testing conditions of MDSC, such as temperature (T), linear heating rate (β), modulated amplitude (A_T) and modulated period (ρ), were studied. The results showed that the measured specific heat (C^ms_p) increased with the increase of T and ρ, while was hardly affected by β andA_T. The relative error (E^ms_r) betweenC^ms_p and literature value (C^std_p) reached a minimum value when an optimum ρ was kept to be 30 s, which was less than 3% in the temperature range from 100 to 200 ℃. An emendation parameter to modify C^ms_p was obtained. The modified C^md_p shows good agreement with the literature C^std_p, The relative error E^md_r between C^md_p and C^std_p was less than 1.5%， when the temperature varied from 100 to 200 ℃ and the ρ value changed from 20 to 50 s.