Heat capacity studies of rare earth 1:2 iron intermetallic compounds, 1. 5 - 20 K
A computer-controlled pulse calorimeter was used to measure the heat capacities of rare earth 1:2 iron intermetallic compounds between 1.5 and 20K. Samples produced at the University of Pittsburgh and samples of higher purity from the Ames laboratory DOE were studied. The resulting values were separated into component contributions. After subtraction of the hyperfine and crystal field contributions, ..gamma.. values (electronic contribution) and ..beta.. value (lattice contribution) were obtained by a least squares fit of an equation relating these two quantities and temperature. Oxide contributions below 4K correlating with literature values were observed in many of the compounds. Higher heat capacities observed in the samples produced at the University of Pittsburgh may be due to the presence of interstitial nonmetals. The abundance of nonmetals in the starting materials for the University of Pittsburgh samples were much higher than for the Ames samples. The ..gamma.. value for HoFe/sub 2/ was significantly higher than the ..gamma.. value for the other compounds studied. The difference may have been the result of a magnetic spin wave contribution. With two exceptions the Debye temperatures of the RFe/sub 2/ compounds increased with increasing rare earth atomic weight, and in both of the exceptions, it is possible that spin-wave contributions may have resulted in an increase in the ..beta.. values observed.
- Research Organization:
- Pittsburgh Univ., PA (USA)
- OSTI ID:
- 5529045
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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