A low-temperature technique for measuring enthalpies of formation
- Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
A technique to accurately measure the formation enthalpies of transition metal compounds at relatively low temperatures using thick multilayer foils and differential scanning calorimetry is demonstrated. The enthalpy of formation of Cu{sub 51}Zr{sub 14} was measured using 25 {mu}m thick, free-standing Cu{endash}Zr multilayer foils. The multilayers were deposited onto Si substrates using a planetary, magnetron source sputtering system. They were removed from their substrates, cut into 6 mm diameter specimens, and scanned in temperature from 50{degree}C to 725{degree}C in a differential scanning calorimeter. Three distinct exothermic reactions were systematically observed. The heats from the first two reactions were summed and then analyzed using a simple model that accounts for interfacial reactions and heat losses during deposition. The enthalpy of formation for Cu{sub 51}Zr{sub 14} was measured to be 14.3{plus_minus}0.3 kJ/mol. This quantity agrees with the single value of {Delta}{ital H}{sub {ital f}}=14.07{plus_minus}1.07 kJ/mol reported in the literature for this Cu{endash}Zr compound. The advantages of measuring formation enthalpies using thick multilayer foils and low temperature calorimetry are discussed. {copyright} {ital 1996 Materials Research Society.}
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 285863
- Journal Information:
- Journal of Materials Research, Vol. 11, Issue 6; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
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