Measuring enthalpies of formation using thick multilayer foils and differential scanning calorimetry
The ability to measure formation enthalpies of compounds at relatively low temperatures using thick multilayer foils and differential scanning calorimetry is demonstrated. Cu/Zr and Al/Zr multilayers were deposited onto Si and glass substrates using a planetary, magnetron source sputtering system. The as-deposited foils were removed from their substrates and heated from 50 to 725C in a differential scanning calorimeter (DSC). The Cu/Zr samples, which are all Cu-rich, showed three distinct, reproducible, and exothermic solid state reactions. The heats from the first two reactions were summed and analyzed to measure 14.3{plus_minus}0.3 kJ/mol for Cu{sub 51}Zr{sub 14}`s enthalpy of formation. This quantity agrees with the single value of {Delta}H{sub f} = 14.07{plus_minus}1.07kJ/mol reported for this compound. The composition of the Al/Zr multilayers ranged from 8 at% Zr to 64 at% Zr. These samples showed a variety of distinct, reproducible, and exothermic solid state reactions. The total heats from these reactions were summed and analyzed to measure enthalpies of formation for five different Al-Zr alloys. The results compare favorably with literature values of {Delta}H{sub f}. Advantages of measuring enthalpies of formation using thick multilayer foil samples and low temperature DSC calorimetry are discussed.
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 106739
- Report Number(s):
- UCRL-JC--118964; CONF-950412--35; ON: DE95015884
- Country of Publication:
- United States
- Language:
- English
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