A FUNDAMENTAL INVESTIGATION OF THE ALLOYING BEHAVIOR OF THE RARE EARTHS AND RELATED METALS
Final technical rept. for 1 Nov 1959-31 Oct 1962
DENVER RESEARCH INST CO
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The vapor pressures of praseodymium, neodymium, and samarium were measured with a Knudsen effusion apparatus. Also, using the same apparatus, thermodynamic activities of the liquid phase of the praseodymium-neodymium system were deter mined. Heats of vaporization were established from the vapor pressure data for praseodymium, neodymium, and samarium. The phase diagram for the praseodymium-neodymium system was determined from thermal analyses, metallographic examina tions, and X-ray diffraction studies. Results of the thermodynamic activity studies and measurements of solid room-temperature and liquid densities indicate ideal behavior in both liquid and solid solutions, within the experimental error. Ideal behavior was predicted for the praseodymium-neodymium system, as there are essentially no differences between the component elements in considering such variables as electronic structure, crystal structure, atomic diameter, valency effect, electronegativity, and electron concentration.
- Metallurgy and Metallography