The heat capacity of gold-nickel alloy containing 52 atomic per cent gold has been measured in the temperature region 13' to 300ยฐK. The lack of conformity of the data to the Kopp-Neumann rule has been shown. The excess entropy, arising mostly from the change in the vibrational spectrum upon alloy fo
Calorimetric investigations of a gold-nickel alloy. II. The heat capacity at high temperatures and the entropy of formation
โ Scribed by R.A Oriani
- Publisher
- Elsevier Science
- Year
- 1955
- Weight
- 671 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0001-6160
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โฆ Synopsis
The literature of measurements of the heat capacity of alloys is critically reviewed. A Bunsen ice calorimeter is employed to measure the cumulative enthalpy difference between the solid solution Auo.~rrNi~.~a3 and the corresponding weights of the pure metals; differentiation of the temperature curve yields the deviation of the heat capacity of the alloy from the Kopp-Neumann rule. The positive value of this deviation and the large magnitude of the vibrational entropy of solution are related to the loosening of the lattice that accompanies formation of the solid solution.
MESURES
CALORIMETRIQUES SUR UN ALLIAGE OR-NICKEL. II. CAPACITE CALORIFIQUE A HAUTES TEMPERATURES ET ENTROPIE DE FORMATION Discussion de la litterature sur les mesures de capacite calorifique des alliages. Emploi d'un calorimetre de Bunsen pour mesurer les differences d'enthalpie entrie les solutions solides Aug.~~rNi".483 et les metaux purs correspondants, en fonction de la temperature. La capacite calorifique de cet alliage ne suit pas la regle des melanges. La valeur positive de l&art et la grande entropie de vibration de cette solution sont attribuees au relachement du reseau qui accompagne la formation de la solution solide. KALORIMETRISCHE UNTERSUCHUNGEN AN EINER GOLD-NICKEL-LEGIERUNG. IL WARMEINHALT BE1 HOHEN TEMPERATUREN UND BILDUNGSENTROPIE In der Literatur mitgeteilte Methoden zur Messung des Warmeinhaltes werden kritisch besprochen. Die Differenz der Restenthalpie zwischen der festen Liisung Auo.arrNio.ns3 und den entsprechenden Gewichten der reinen Metalle wurde mit einem Eiskalorimeter nach Bunsen gemessen; die Differentiation der Temperaturkurve enthiilt die Abweichung von der Kopp-Neumannschen Regel. Der positive Wert dieser Abweichung und der grosse Wert der Schw~gungsentropie bei der Losung werden auf die Auflockerung des Gitters zuriickgefiibrt, die die Bildung der festen Losung begleitet.
๐ SIMILAR VOLUMES
The heat capacity of synthetic Cu3AsS4 (enargite) was measured by quasi-adiabatic calorimetry from the temperatures 5 K to 355 K and by differential scanning calorimetry from T=339 K to T=720 K. Heat-capacity anomalies were observed at T=(58.520.5) The causes of the anomalies are unknown. At T=298.