I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2008, #11/12
http://www.materials.kiev.ua/article/1326

Abstract

The heat capacity and enthalpy of Ce5Si3 is examined for the first time over a wide temperature range. The values of heat capacity, entropy, reduced Gibbs energy (J · mole-1 · K-1), and enthalpy (J · mole-1) are determined at 298.15 K: Сp°(Т) = 230.62 ± 0.93; S°(Т) = 352.0 ± 2.8; Ф′(Т) = 185.2 ± 2.8; Н°(Т)–Н°(0 K) = 49744 ± 249. The temperature dependences of Ce5Si3 enthalpy (J · mole-1) are determined as Н°(Т)–Н°(298.15 K) = 19.934 · 10-3 · T2 + 245.26 · Т + 2358300 x Т-1 – 82807; Н°(Т) – Н°(298,15 К) = 413,78 · Т – 123368 for 298.15–1564 K and 1745–1806 K, respectively. The temperature, enthalpy, and entropy of Ce5Si3 melting are calculated as follows: Tm = 1564 ± 30 K, ΔНm = 172.7 ± 12.2 kJ · mole-1, and ΔSm = 110.4 ± 7.8 J · mole-1· K-1.


ENTHALPY, ENTROPY, HEAT CAPACITY, REDUCED GIBBS ENERGY, SILICIDE, THERMODYNAMICS